Does cement increase water hardness in an aquarium? Water hardness in an aquarium and ways to normalize it

The text of this section is based on, with the permission of the authors, an article from Mikluha's Aquasite website (c) Michael Dubinovsky a.k.a Mikluha.
All drawings and photographs in this section (c) Michael Dubinovsky a.k.a Mikluha.

pH measurement

As stated above, the acidity of the water, measured by pH, is an important parameter of the aquarium.

Different fish prefer different pH values. Knowledge of this parameter is necessary when diagnosing fish. If your fish suddenly become ill, the first thing to check is the pH value of the water (along with the ammonia).

The simplest pH test is based on the use of color-changing reagents and litmus papers - phenolphthalein, etc. (remember the chemistry course at school?). There is a huge variety of aquarium tests. You can also buy such a reagent separately (remember that they have an expiration date, so do not buy a 100 liter barrel for life). such tests are easy to use and quite accurate - you do not need to know the pH value with an accuracy greater than 0.1-0.2. All the same, in an aquarium, as in nature, daily fluctuations in pH occur. Fish and plants release carbon dioxide at night and the pH decreases, depending on the carbonate hardness of the water. During the day, on the contrary, plants absorb carbon dioxide during photosynthesis and this leads to an increase in pH value. Daily fluctuations of 0.5-1 units are quite acceptable. You should have a test that measures pH values ​​in the range of 5.5 - 8.0 for most fish. African cichlids require a test that measures higher pH values.

Various companies produce many types of aquarium tests.

Another way is to use electronic testers. They come in two types: one is designed only for measuring pH (you immerse it in water and it produces a pH value - pH tester, pH meter), the other can produce a signal to control some device (for example, to control the supply of carbon dioxide) they are constantly in the water (pH controler).

• The advantages of such devices include:
• speed of obtaining results
• accuracy (average accuracy - 0.05 - 0.1 pH value units)

the ability to constantly monitor changes in pH and receive a control signal. Some can be connected to a computer.

• But they also have their disadvantages:
• The need for their periodic calibration, and quite often. They are usually calibrated at two points (one neutral pH=7, the other pH=4 or pH=10). In this case, it is necessary to have a fresh solution for calibration (they have an expiration date).
• You must either have a meter with automatic temperature compensation or calculate corrections to the result yourself, depending on the water temperature,
• The service life of the electrode - the main part of such a meter - is approximately about a year for continuous operation (of course depends on the type of electrode),
• They must be thoroughly washed before use and the electrode must be kept moist.

In general, their use is quite a hassle and it makes no sense for novice aquarists to buy them.

Hardness of water

Hardness is the second most important parameter for an aquarium, along with acidity.

The hardness of water is determined by the presence of minerals dissolved in it and largely determines the other properties of water. Despite the huge number of different minerals dissolved in water, only a few determine its hardness - it so happened historically that the most important application was the ability of soap to lather in water. Hence all the definitions. Even some methods of measuring hardness are based on this. Water hardness is divided into two parts - constant (GH, general hardness) and variable (carbonate), KH, carbonate hardness). Sometimes they talk about overall hardness, which is the sum of these parts.

The division of hardness into these two parts is determined by what mineral salts remain in the water after boiling water (constant hardness). Quite a practical definition. Salts that determine carbonate hardness precipitate because, for example, for calcium: 3 ) 2 <->Ca(HCO 3 CaCO 2 +H 2

O+CO

Carbonate hardness is determined by the concentration of carbonates CO 3 - and bicarbonates HCO 3 - in water (mainly bicarbonates are present in aquarium water, since carbonates exist in significant concentrations at high pH>9). It characterizes the buffering ability of water to resist changes in pH - over time, the pH value drops due to the presence of organic matter in the water. In the aquarium, this term and the concept of buffering capacity (alkalinity) are used interchangeably, since all aquarium tests for measuring KN are based on the titration method, i.e.

changing the color of a solution when a certain amount of acid is added to it, which binds all free buffer ions. The number of acid drops determines the KN value. Since the acid does not “distinguish” which ions (carbonates, bicarbonates, etc.) are involved in neutralization, it is impossible to find out the KN value in its pure form. And this is not necessary, since it is this ability of water that is always of interest. Usually, in the absence of phosphates and boron salts in high concentrations, alkalinity is almost completely determined by KN.

Another confusion arises from the fact that the total hardness, equal to the sum of the constant and the variable (carbonate), is often spoken of as constant, meaning GH as the total hardness.

• However, aquarium tests measure permanent hardness separately, denoting it as GH. Increasing hardness - change their values ​​smoothly, otherwise you can cause stress in fish and other problems:
• KH- one teaspoon of sodium bicarbonate (baking soda) per 50 liters of water will increase KH by approximately 4 degrees dKH,

G.H. - two teaspoons of calcium carbonate per 50 liters of water will simultaneously increase KH and GH by 4 degrees. Therefore, by varying the components, you can select the required stiffness values. You can also add Ca/Mg sulfate, which will not cause an increase in KH, but will lead to an increase in the concentration of sulfate ions, which is not very good.

• Reducing hardness - a much more complex problem: Use distilled water, which is sold in stores. Or rainwater, if you are sure of its purity.
• Filtering water through special filters - osmotic filter and deionization
• Filtration of water through various resins that are commercially available. The disadvantage of this method is that usually only one resin is used (anions or cations are removed) and they are replaced not with hydrogen ions H + and OH - ions, but with other ions - for example, Ca, Mg ions with sodium, which is not very good for plants. Therefore, it is not recommended to use household water softening compounds (for example, for a swimming pool).
• The simplest and most convenient way is to filter water through peat. To do this, peat is added to the filter (external or internal). Another way is to add peat (for example, poured into an old sock) into a container where the water settles.

For some fish. requiring very soft water for spawning, peat can be used as a substrate. The disadvantage of peat is that it colors the water yellowish (which can be removed by filtration through activated carbon). In addition, it is better to boil the peat.

Other water parameters are conductivity, oxidation potential, etc.

In addition to the main parameters, there are other parameters that can be used to characterize water. They are rarely used in the aquarium, so they are described very briefly.

Conductivity is a quantity that measures the ability of water to conduct electricity. This ability is determined by the presence of positively and negatively charged ions, their mobility, temperature, etc.

Most inorganic salts dissolved in water increase the water's ability to conduct electricity. Conductivity is the reciprocal of resistance and is measured in siemens. It is designated either S or mho (ohm - written in reverse order). The conductivity of absolute pure water, where only H + and OH - ions are present, at room temperature is approximately 20 MOm/cm (0.05 mkS/cm). In reality, the conductivity of distilled water will increase quickly due to the dissolution of carbon dioxide in it. Conductivity is measured with a special meter, which essentially measures the current in the water that has filled a cell with standard electrodes. In principle, you can use a megohmmeter specially calibrated with electrodes placed in a container at a certain distance. This measurement is useful for determining the quality of osmotic filtration and de-ionization.

On average, tap water has a conductivity varying from 50 to 1500 mkS/cm

There is an approximate relationship between TDS and conductivity:

TDS mg/l = 0.64 mkS/cm

This ratio is empirical and may vary slightly for your tap water.

Approximate relationship between table salt concentration and conductivity:

As everyone learned at school, there are two types of reactions - oxidative and reduction. The first include those as a result of which molecules “lose” electrons (for example, the nitrate cycle, as a result of which ammonia is converted into nitrates), the second are reverse reactions - for example, the reduction of a nitrate molecule back into ammonia (this is done by plants in the process of “receiving "nitrogen). Atoms such as oxygen or chlorine are extremely hungry for electrons and are therefore oxidizing agents. Others, such as hydrogen and iron, have “extra” electrons and are reducing agents. The difference in the charges of oxidizing agents and reducing agents in water is called the oxidation-reduction potential. Quite simple, although it seems terribly incomprehensible. If there are more oxidizing agents in the water, then the potential is positive and vice versa. ORP is measured in millivolts.

The decomposition of organic matter in water is an oxidative reaction. The accumulation of organic matter in water increases the concentration of reducing agents and reduces the ORP value. The higher this value, the more oxidizing agents (mostly oxygen - you're unlikely to use chlorine in your aquarium) are present in the water, the more organic matter can be broken down and the cleaner the water. On the other hand, high ORP can be harmful to fish and other organisms as it can destroy living cells. The optimal value lies between 250 and 400 mV. The ORP value depends on many factors and can fluctuate in an aquarium, for example, ORP decreases as temperature increases and pH decreases.

ORP is measured by special meters similar to pH meters (meters with different electrodes using different solutions for comparison give different results). You can increase the ORP of water by regularly changing the water, cleaning the aquarium, air purging and using ozone.

Oxygen and carbon dioxide

The main gases dissolved in water are (as in the atmosphere) oxygen, carbon dioxide and nitrogen. the most easily soluble is CO 2, the relative solubility of carbon dioxide is approximately 70 times higher than the solubility of oxygen and 150 times higher than the solubility of nitrogen. Nitrogen has virtually no effect on the life of organisms in the aquarium, except for blue-green algae, which can absorb it. The table shows the saturation levels of dissolved oxygen and carbon dioxide in water (the saturation level shows the maximum amount of gas that can dissolve in water, but not the equilibrium level, which, for example, for carbon dioxide at room temperature is about 2 mg/l).

As can be seen from the table, the solubility of carbon dioxide is hundreds of times higher than the solubility of oxygen. The main processes in which oxygen and carbon dioxide are involved are:

• The respiration of fish, which, like us all, breathe oxygen and emit carbon dioxide.
• Respiration and photosynthesis in plants Plants use oxygen for respiration. In doing so, they release carbon dioxide.
• It is usually believed that the process of plant respiration occurs in the dark, but this is not so. It occurs all the time, including in the light, simultaneously with the process of photosynthesis, during which carbon dioxide is absorbed and oxygen is released.
• Bacteria and other microorganisms consume oxygen. This is often forgotten about all the processes of decomposition of organic matter in an aquarium, including the bio-filtration necessary in an aquarium.

Other chemical processes, for example, when soil rots, hydrogen sulfide H 2 S is released, which requires oxygen for its oxidation.

Fish that live in nature in oxygen-poor water have adapted to such conditions, for example, labyrinth fish, which naturally live in any puddles, can “swallow” air. On the other hand, many fish, such as African cichlids from Lake Malawi, require water rich in oxygen.

On average, you should try to ensure that the oxygen level does not fall below 7 mg/l in the aquarium. Fish living in low oxygen concentrations are more susceptible to diseases, fry are delayed in development, etc.

With a lack of oxygen, fish begin to take in air from the surface, which subsequently leads to carbon dioxide poisoning. Fish that have died from asphyxia usually have a wide open mouth and protruding gills that are pale in color (although similar symptoms can occur with other diseases).

Despite popular belief, carbon dioxide does not displace oxygen from water. The level of dissolved carbon dioxide in water depends on many parameters. An excess of carbon dioxide leads to poisoning of fish, which fall into a coma and die.

The easiest way to maintain high oxygen levels and low carbon dioxide levels in the water is to aerate and mix the water with pumps. In this case, oxygen dissolves in water, and carbon dioxide escapes into the atmosphere. You should ensure that there is no greasy or bacterial film on the surface of the water, which impedes gas exchange. Try not to raise the water temperature higher than necessary for the normal life of this type of fish. At high temperatures, the solubility of oxygen in water decreases, and the need for it increases.

Another way is to grow plants that absorb carbon dioxide and release oxygen. Paradoxically, in bright light, plants are able to release more oxygen than can be dissolved in water - oxygen bubbles will rise from the plants

Of course, you can dissolve oxygen in water from a cylinder, but this method is complex because it requires a special reactor and control. Otherwise, you can poison the fish with an excess of oxygen.

Heavy metals contained in tap water are toxic to all organisms, even those that are necessary in small doses for successful plant growth (zinc: copper, nickel, etc.). Even if the metal content in water meets the maximum permissible standards established for humans, such water can be dangerous for fish. This is especially true for copper and zinc, which are not toxic to the human body in reasonable concentrations.

Metals are toxic because they can “attach” to organic molecules, disrupting their functions. For example, mercury combines with the -SH group, which is found in most proteins.

Metals are especially toxic to fish fry. For example, the maximum copper concentration, above which the mortality of trout fry increases, is 0.010-0.017 ppm. The maximum concentration of lead, above which “deformation” of trout fry occurs, is 058-0.12 ppm.

Also, metals can be toxic to plants at high concentrations, even though they are needed in low concentrations for normal plant growth. For example, the most common overdose is iron, which is added as fertilizer to water, and the leaves turn brown and become stained. The symptoms are similar to those of phosphorus deficiency. Slow-growing plants, for example, cryptocorynes, which do not have time to “process” the increased concentration of iron, may especially suffer.

The toxicity of metals depends on many water parameters:

Preparation of tap water

The main source of water for an aquarium is tap water. At the waterworks, it is treated in one way or another so that bacterial jelly does not pour out of the tap. Leaving aside any exotic methods of water disinfection, such as ozonation (at least, I have not seen such water stations), water is disinfected either with chlorine or chloramine. Chlorine, used in the traditional method for water disinfection, easily evaporates when the water is stirred. It is enough to let the water sit overnight in a wide container so that the chlorine evaporates. And if you are changing a little water in the aquarium and the stream is sprayed into separate drops, then you can pour it directly into the aquarium. Another way is to use dechlorinators (either commercial ones, which are sold in aquarium stores, or use sodium thiosulfate) or activated carbon

On the other hand, try to find out what kind of water flows from your tap. This will make your life easier. It is much easier to increase water hardness (for example, for cichlids from Lake Tanganyika), but the opposite is more difficult - you need to filter the water through ion exchange resins, etc. Therefore, consider first whether you can do this for a long time before getting discus if you have artesian water flowing from your tap, which resembles Tanganyika.

Instructions

Stiffness is most often divided into permanent and temporary. Temporary is also called carbonate, it is associated with the presence of calcium and magnesium ions in water, which can be removed by boiling. Measuring carbonate hardness is usually done by boiling a certain amount of water and weighing the resulting sediment. But in practice this is quite difficult to do, so the following method is used: prepare the necessary reagents and equipment. You will need distilled water, a 38% solution of hydrochloric acid (you can buy it at a hardware store or take it from a school chemistry classroom), methyl orange indicator, laboratory glassware, a syringe without a needle.

Prepare the required hydrochloric acid solution. To do this, dissolve 4 ml of purchased hydrochloric acid in 300 milliliters of distilled water. Then increase the volume of the solution to a liter. Be extremely careful: acid contact with skin will cause severe chemical burns. Do not inhale acid fumes and when diluting, be sure to add acid to water, and not vice versa.

Hardness is calculated as follows: water hardness = (acid concentration * volume of acid) / amount of water. The carbonate hardness will be equal to the volume of acid consumed. To convert the resulting value from ml/eq to degrees, multiply it by 2.804.

When keeping fish, you don’t immediately think about the hardness of water in an aquarium. As a rule, many hobbyist aquarists never even think about it. After all, aquarium fish can live in water hardnesses that are slightly different from those recommended for them. As a rule, such subtle nuances are more of a concern to professionals who do not just look at the beauty of swimming fish behind the glass of an aquarium, but to those who truly “live” this underwater world.

Such seemingly insignificant criteria as water hardness can affect the growth and final size of fish, their fertility, and their quality of life. And so, if you have already reached the level of understanding how to determine and how to control the level of water hardness in an aquarium, then perhaps without wasting your time on an additional voluminous introduction, we will begin to present the main material of our article.

What is water hardness, a physical concept with a popular explanation

If we talk about hardness in popular terms, then this is a certain content of salts of the so-called alkaline earth metals (Beryllium, Magnesium, Calcium, Strotium, Barium, Radium, Unbinilium). Although all these metals belong to the above-mentioned alkaline earth metals, nevertheless, due to their greatest distribution In water there is mainly calcium and magnesium; salts of these metals can be characterized as having the greatest effect on water hardness.

If we give examples for hard water, these are, first of all:

Significant scale after evaporation (boiling) of water;

Hard water is bad for soaping.

The properties of soft water are characterized as follows:

On the contrary, no scale remains,

Iron corrodes more intensively in it due to the lack of an acid-base buffer.

Well, if we talk about the benefits of both waters, then you won’t get a definite answer from anyone. Water for living organisms, including humans, must have a certain hardness. So low hardness affects the development of cardiovascular diseases, increased hardness affects the formation of stones. Deviations in water hardness will not have the best effect on fish.

How is water hardness measured in an aquarium?

The hardness of water in an aquarium, and not only in it, is measured in different units. The phrase is quite spatial, but it is the one that describes the current situation most correctly. The thing is that in the world there is still no single standard, GOST or any other regulatory document, according to which all countries must use certain selected units of measurement of water hardness.
If we talk about Russia, since 2005 our country has introduced a standard according to which water hardness is measured in degrees of hardness - °Zh. 1 °F corresponds to the concentration of the metal salt that we talked about earlier, numerically equal to 1/2 of its mole per liter (1 °F = 1 mEq/l). To put it simply, this is the content of 10 mg of calcium oxide or 7.19 mg of magnesium oxide in one liter of water.
As we said, water hardness in other countries is indicated in alternative ways. Below we will provide a table that shows the name of the unit of measurement of hardness in accordance with the country and the relationship with the degree of hardness according to the Russian standard.

Relationships between quantities measuring water hardness

Conventional water hardness levels

In fact, this conditional division of water hardness implies certain limits within which water is considered soft, medium hard and hard, like this:

Soft water up to approximately 3.6 °F,

Medium hardness 4-8 °F,

Hard more than 9 °F.

These indicators and criteria are applicable relative to the Russian degree. See table above.

How to measure water hardness in an aquarium

The simplest and most accurate way, of course, is the cruelty test, which is sold in some pet stores. But not all aquarists have such an alternative, due to its cost or the impossibility of purchasing something similar in their region. Therefore, we will consider an alternative option.
It is known that soap with a percentage of fatty acids of about 65 percent (household soap) weighing 1 gram reacts with 10 mg of metal salts (calcium and magnesium).
As a result, we dissolve laundry soap weighing 1 gram in water (10 ml). We take 0.5 liters of water in which we need to determine the hardness. Gradually pour the soap solution into the jar, 1 ml at a time, close it with a lid each time and shake. As soon as a stable foam appears after the next addition of a soap solution, this will mean that all metal salts have reacted with the soap.

Now you need to multiply the number of milliliters of soap solution added by 2 and you will get the value of water hardness in degrees. The error will depend on the accuracy of all operations. At best it will be on the order of ±1°.

How to change (decrease, increase) water hardness in an aquarium

To reduce water hardness

First of all, to change the hardness of water downward, boiling is suitable. When boiling, metal salts will precipitate, and eventually they can be filtered. But it is better to collect water from the upper layers for filtration, and completely drain the lower layers.
You can also use soda, which will also react with the salts and the solid sediment can be collected. You can use all kinds of filters to purify water. Cationic filters, osmosis filters. Of course, these filters are very expensive to buy just for an aquarium, so this is more suitable if you have such systems for purifying water for your own needs.

To increase water hardness you can:

Boil the water, but collect the bottom layer where the sediment will be concentrated. - add small pieces of limestone, chalk, shells, marble chips or colored glass;
- you can add magnesium and calcium chloride (for example, 25% magnesia at the rate of 1 ml of solution per 1 liter of aquarium water) or soda (at the rate of 1 teaspoon per 50 liters of water) - this will increase the hardness of the water in the aquarium by about 4 degrees;
- add 10% calcium chloride to the aquarium water (at the rate of 1 ml per 1 liter of water) - this will increase the hardness of the water in the aquarium by about 3 degrees;
- decorate the aquarium with rapan shells or coral chips.

Very often, having decided to get into aquarium keeping, hobbyists carefully choose a container for their home pond, think about where to place it, what fish and plants to fill it with. However, they completely forget about the main and most important component of this entire system - water. As a rule, aquariums are filled with the most easily accessible water, most often tap water. Few people think about its parameters. And if he thinks about it, it’s only about whether it’s suitable for fish. However, plants are no less demanding of water, although they react more slowly to its quality.

In this article we will touch on one of the important parameters – rigidity. After all, it depends not least on her whether the aquarium will become the way it was intended or not.

What is the hardness of water in an aquarium?

It is considered the second most important water parameter after acidity. The possibility of keeping and breeding fish and plants depends on it. It affects other properties of water.

This parameter is determined by the presence of certain minerals that are dissolved in water. The overall stiffness consists of two parts:

Constant (GH). It is paramount, as it determines the softness or hardness of the water and the degree of its suitability for the inhabitants of the aquarium. GH determines the concentration of Ca++ and Mg++ ions in water. Boiling leads to the destruction of bicarbonates and precipitation of calcium and magnesium. The hardness that remains after boiling is called constant. It is measured in degrees of hardness. And all tests are released in them.

Variable or carbonate (KH). It is determined by the concentration of carbonates CO3- and bicarbonates HCO3- in water.

Aquarium water hardness is normal

The importance of water hardness in the life of the inhabitants of a home pond is great:

• magnesium and calcium salts are involved in the construction of the skeleton and skeletal system of fish;

• in mollusks and crustaceans they provide the hardness of the shell or shell;

• rigidity promotes normal functioning and development of the genital organs;

• it affects the success of plant growth and development, etc.

Hardness can be of varying degrees of intensity: 0-4 - very soft, 5-8 - soft, 9-16 - medium hard, 17-32 - hard, 33 or more - very hard. Tap water usually has a hardness of no more than 20.

The water hardness in the aquarium must be within certain limits, usually this range is 3-15 degrees. It is better if for each specific species the indicators are close to the natural conditions of their native reservoirs.

For example,

• snails require hard water, as their shells are destroyed in soft water;
• viviparous fish will feel good at 10,
• neon at 6,
• sagittaria and fern at 10-14 degrees, etc. This information can be found in the recommendations for caring for a particular species.

You also need to take into account that the inhabitants of the aquarium absorb calcium, so its amount in the water will gradually decrease. It is easier to maintain the hardness at the same level if the soil is pebbles or coarse sand. And, of course, regular measurements will be required.

How to determine the hardness of water in an aquarium?

The main methods are:

Chemical reagent Trilon "B"

This is a very accurate method, but its disadvantage is that it is too complicated for people who are not very interested in chemistry, and not everyone wants to have additional chemical equipment at home.

TDS meter

He is also a conductometer, he is also a salinity meter. The method is very simple. However, this electronic device does not measure the hardness itself, but the electrical conductivity of the water, which can only be used to indirectly judge the hardness.

Test strips

They have been specially developed for measuring water hardness in aquariums. Simple and easy to use. There is an option where a reagent is added to the specified volume of water and the hardness is judged by the changed color. All calculations are made according to the instructions included in the kit. This method has one drawback - such sets are difficult to buy, since they are rarely on sale.

Laundry soap

This is the most accessible, cheapest and most accurate method at home. It is based on the property of soap: it is difficult to dissolve in hard water and produces foam when there is an excess of calcium and magnesium salts.

How research is carried out:

1. Grind laundry soap (1 gram) and carefully pour into a small amount of heated distilled water (sold in auto stores).

2. Pour the resulting solution into a glass and add distillate so that its height reaches 6 cm for 60% soap and 7 cm for 72% soap. Each centimeter of such a solution contains as much soap as is required to bind salts, the amount of which is equal to 1 ° dH in 1 liter of water.

3. Fill a 1 liter jar halfway with water from the aquarium.

4. Pour the prepared solution into it a little at a time, stirring constantly. First, flakes will appear on the surface, and then a stable soap foam, which indicates that all the salts in the water are bound.

Evaluation of the result. Count how many centimeters of solution were poured into the water. 1 cm tied in 0.5 liters of water 2°dH salts. That is, if 4 cm is poured, then the hardness is 8 degrees, etc. If the entire solution is poured out, but there is no foam, then the hardness is above 12 degrees. Then dilute the water for testing with distillate twice, repeat the analysis, multiplying the results by two.

The results may have an error of 1-2 degrees, but this is not critical and will not lead to illness or death of the inhabitants of the aquarium.

If the hardness of the water available to the aquarist does not correspond to what he needs to maintain the aquarium inhabitants, then it can be changed. But this needs to be done smoothly so as not to cause stress or other problems in your pets.

How to increase water hardness in an aquarium?

1. Mix aquarium water with harder water.

2. Boil water for about an hour. It is better to take enamel dishes. Next, cool it and carefully drain the two upper parts of the volume. Pour the lower third, rich in calcium salts, into the aquarium in portions, controlling the hardness by measurements.

3. Place pieces of shells, marble or limestone rocks into the aquarium to increase the overall hardness by 2-4 degrees. The disadvantage of this method is the inability to control the level of rigidity. It is more preferable to filter the aquarium water through a layer of crushed marble, decreasing or increasing the amount of water passing through the filter.

4. Add baking soda in the amount of 1 tsp. per 50 liters of water to increase variable hardness (KH) by 4 degrees.

5. Add calcium carbonate at the rate of 2 tsp. per 50 liters of water to increase constant (GH) and variable (KH) hardness by 4 degrees.

6. Add to the water a ten percent solution of Ca chloride (can be purchased at a pharmacy) and magnesium sulfate (prepare it yourself: dissolve 50 g of bitter salt to obtain 750 ml of solution) in equal proportions (1 ml of each per 1 liter). The hardness will increase by about 4 degrees.

7. Pour in magnesium in a 25% solution (1 ml per 1 liter of water). This will raise the stiffness by 4 degrees.

How to reduce water hardness in an aquarium?

This is much more difficult to do. The methods are as follows:

1. Add distilled, melted or clean rainwater.

2. Boil water, cool it without stirring, and drain 2/3 of it from the surface. Add this top water to the aquarium.

3. Freeze. Pour water into a low container, for example, a basin. Refrigerate. After half of the ice has frozen, break through the ice, pour out the unfrozen water, and melt the ice. Add the resulting water to the aquarium.

4. Pass the water through special filters (osmotic and deionization).

5. Filter the water through peat added to an external or internal filter or placed in a bag in a container with settled water. The peat for the soil must first be boiled. In some spawning grounds, peat is used as soil. The yellow tint it gives to water can be removed by filtration through activated carbon.

6. You can add a decoction of alder cones. But its hardness decreases slightly and the composition of the water may change, which is not good in all cases.

7. Use Trilon-B and EDTA according to the instructions.

8. Plant elodea, egrosaw and hornwort.

Now you know what water hardness in an aquarium is, how important it is for its inhabitants, and you have an idea of ​​how to measure and change it. We hope this information helps you create the aquarium of your dreams. Good luck!

How to increase water hardness:: water hardness in an aquarium:: Natural Sciences

To breed and maintain aquarium fish, you need to: rigidity water was constant in the aquarium. If the aquarium soil consists of coarse sand and river pebbles, then the water in the aquarium will always have a certain rigidity. In aquariums containing fish and shellfish, rigidity decreases over time due to the consumption of calcium by mollusks to build shells. Therefore, it needs to be increased periodically.

The question “And yet! What came first? “Egg or chicken?” - 12 answers

You will need

• - carbonate rocks;
• - 10% solutions of CaCl2 and MgS04;
• - 25% magnesia solution;
• - distilled, rain or melt water.

On the other hand, try to find out what kind of water flows from your tap. This will make your life easier. It is much easier to increase water hardness (for example, for cichlids from Lake Tanganyika), but the opposite is more difficult - you need to filter the water through ion exchange resins, etc. Therefore, consider first whether you can do this for a long time before getting discus if you have artesian water flowing from your tap, which resembles Tanganyika.

1. To increase rigidity water, boil it in an enamel bowl for one hour. Carefully pour off two-thirds of the water Gradually pour the remaining calcium-enriched mixture into the aquarium in a thin stream.

2. Prepare or buy at the pharmacy a 10% solution of calcium chloride (CaCl2) and a 10% solution of magnesium sulfate (MgS04). To increase rigidity water per 1 °dGH add per 100 l water 18.3 ml of 10% calcium chloride (CaCl2) or 19.7 ml of 10% magnesium sulfate solution (MgS04). To maintain the required ion ratio for fish and plants, add these solutions in approximately equal quantities.

3. To increase carbonate hardness, add carbonate rocks (dolomite, chalk, marble, etc.) to the aquarium water or pass it through marble chips. But remember that the dissolution of carbonate rocks in water is possible only in the presence of carbon dioxide: CaCO3 + CO2 + H2O -> Ca(HCO3)2 To do this, add sparkling water to the water or for saturation water CO2 use a special device.

4. To increase carbonate rigidity at 1° dKH, dissolve 1.5 g of MgCO3 (magnesium carbonate) or 1.8 g of CaCO3 (calcium carbonate) in 100 ml. But it is better to use both salts in equal parts. Add a 25% magnesium solution to the aquarium water at the rate of 1 ml per 1 liter water- so you will increase rigidity water at 4H°.

5. Mix settled tap and distilled water. If rigidity water from the tap - 10 N°, then mix 7 parts distilled water with 3 parts tap water to get aquarium water rigidity yu 3 N°.

6. In the absence of distilled water in cities and villages with low air pollution, replace it with rain or melt, rigidity which is 2-3 N°.

7. Place rapan shells or coral chips on the bottom of the aquarium. Boil them for an hour first. Change once a week of the total volume 10-15% water, do not overpopulate the aquarium, and rigidity water will not be permanent.

Aquarium water, parameters: hardness, pH and others

One of the most important components of the aquarium world is water, as a habitat for aquarium fish and plants.

The parameters of aquarium water and its characteristics directly affect the well-being of your pets and the condition of plants. It is no secret that dirty, cloudy water kills fish and spoils the appearance of the aquarium, however, clear water does not always mean that its composition is ideal.

The main parameters and indicators of aquarium water quality are:

Aquarium water hardness (hD);

Hydrogen indicator of water “Acidity of aquarium water” (pH);

Oxidation-reduction potential (rH);

AQUARIUM WATER HARDNESS (hD)

Temporary hardness of aquarium water (KH) is the concentration of calcium and magnesium bicarbonate salts formed from weak, unstable carbonic acid. This hardness can change throughout the day. For example, during the daytime, aquarium plants absorb carbon dioxide, which accumulates in the water, through the process of photosynthesis. If there is not enough carbon dioxide for plants to consume, they will begin to produce it from bicarbonates, as a result of which the temporary hardness of water will decrease.

Constant hardness of aquarium water (GH) is the presence of stable calcium and magnesium salts formed from strong acids - hydrochloric, sulfuric or nitric.

How to change the hardness of aquarium water:

1.) Increase in rigidity.

The KH hardness can be increased by adding 1 teaspoon of baking soda per 50 liters, which will increase the readings by 4°dKH.

HOW TO MEASURE the total hardness of aquarium water at home without special equipment. equipment and preparations (sample titration with soap solution):

Hydrogen index of water or “acidity of aquarium water” (pH of aquarium water).

Determines the neutral, acidic and alkaline reaction of water at a certain concentration of hydrogen ions.

In chemically pure water, electrolytic dissociation occurs - the decomposition of molecules into hydrogen (H+) and hydroxyl (OH-) ions, the amount of which in it at a temperature of 25°C is always the same and equal to 10-7 g*ion/l. This water has a neutral reaction. The negative logarithm of the concentration of hydrogen ions is conventionally used to indicate the pH value and in this case is equal to 7. If there are acids in water (not chemically pure water), the number of hydrogen ions will be greater than hydroxyl - the water becomes acidic with a lower digital pH value. Conversely, in alkaline water, hydroxyl ions will predominate and the pH will increase.

Aquarium water with pH parameters:

From 1 to 3 is called/considered strongly acidic;

From 3-5 sour;

From 5-6 slightly acidic;

7 neutral;

7-8 slightly alkaline;

10-14 strongly alkaline;

pH parameters can change throughout the day, which is due to the variable concentration of carbon dioxide in aquarium water, which in turn is stabilized by constant aeration.

Sharp fluctuations in pH levels are harmful and painful for aquarium fish and plants. Most aquarium fish prefer a pH between 5.5 and 7.5.

HOW TO CHANGE the pH of aquarium water:

If it is necessary to lower the pH, acidify the water with peat infusion (or special preparations from the Pet Store);

If it is necessary to increase the pH (increase alkalinity), I use baking soda;

MEASURING the pH of aquarium water:

1. Many pet stores sell testers (litmus papers with phenolphthalein). Actually, following the instructions on the packaging and using the scale, you can determine the pH parameters.

2. There are specials. measuring device – PiAshmeter. It is not used for home aquariums (expensive, and there is no reason for it at all). After all, the main thing is not the frequent measurement of pH parameters, but the conditions of keeping the fish and the aquarium. In a well-groomed aquarium, not overcrowded, not filled to the brim with plants, with aeration, the pH will always be normal and there is no need to measure it often.

Redox potential (rH of water, ORP of water).

The essence of the redox process in aquarium water is that all the substances in it react with each other. In this case, one substance gives up its electrons and becomes positively charged ( oxidizes), and the other acquires electrons and becomes negatively charged ( is being restored). As a result, an electrical potential difference arises between substances of different discharges. Simply put: oxidation is a reaction between nitrites and oxygen, and recovery– on the contrary, the breakdown of nitrites with the release of oxygen.

The maximum oxidative potential of water is 42rH.

Options:

rH 40-42 – maximum oxidation (pure oxygen);

rH 35 – strong oxidation;

rH 30 – slight oxidation;

rH 25 – weak oxidation;

rH 20 – weak recovery;

rH 15 – slight recovery;

rH 10 – strong reduction;

rH 5-0 – maximum reduction (pure hydrogen);

Almost all aquarium fish and plants feel comfortable at rH 25-35. Some species prefer narrower parameters of this value.

rH is measured by special meters.

They increase the rH of the water by regularly changing the water, maintaining it - cleaning the aquarium, as well as blowing air and using ozone.

SO:

We learned about the basic parameters of aquarium water, compliance with which will be an absolute guarantee of the health of the fish and the beauty of the plants.

There are other values/parameters that characterize aquarium water. However, they are not as significant as hD and pH. To maintain a home aquarium, there is simply no need to know and monitor them. As Sherlock Holmes said: “...a smart man carefully selects what he places in his brain attic.”

OPTIMAL PARAMETERS OF AQUARIUM WATER (hD of water, pH of water, ORP of water) THEY ARE OFTEN ACHIEVED BY BANAL CARE OF THE AQUARIUM AND COMPLIANCE WITH THE RULES FOR MAINTENANCE OF ITS RESIDENTS: do not turn the aquarium into a dormitory, do not overload it with plants, ensure constant aeration and filtration, regularly replace the water with fresh water and then the created aquarium world will only delight you!

When creating his own “underwater world,” each aquarist thinks through not only the layout of the accessories, but also the composition of the inhabitants and the placement of all the necessary parts. And very rarely does the thought come to mind about how good the water will fill the volume of the bowl. But this is precisely the question worth thinking about seriously.

Water composition, why it is important and for whom

A deep misconception concerns the fact that the quality of aquarium liquid affects only fish, but is completely unimportant for algae and other representatives of the flora. Hydrophytes are demanding not only about the composition of the liquid, but also about filling it with oxygen and sunlight. However, when the mobile inhabitants of the aquarium show an almost instantaneous reaction to bad conditions, which is quite easy to establish by only monitoring the behavior of the fish, then plants do not have such an opportunity. The slow response of algae makes it difficult to identify the problem immediately.

But what should the water be like? As a rule, tap water is poured, which has been settled for a couple of days. Less often, the bowl is filled with clean liquid from artesian wells, springs or reservoirs, where the habitat is considered the most suitable for the inhabitants of the home “sea”. Owners know little about the characteristics of tap water, but the normal functioning of the inhabitants of your aquarium depends on this.

What is important to know about water:

• indicator of active reaction - pH;
• the presence of certain impurities.

It is also important to consider the influence of biological components that appear from time to time, which sometimes change and thereby affect the characteristics of water. This also needs to be kept under control.

More about water characteristics

A value characterized by approximate constancy relative to a certain area, affecting many other characteristics, as well as ensuring comfortable conditions for all inhabitants of the aquarium. Depends on the presence of calcium and magnesium salts dissolved in a certain volume of water. The measurement is made on a degree scale. Happens:

• softened or soft;
• medium hard;
• hard;
• overly tough.

Indicators for keeping aquarium inhabitants often vary, so it is important to select exactly the hardness that will suit all living individuals in the aquarium.

How to influence the water hardness level

Here are some options:

If your aquarium plants need water of strictly defined parameters, but it is not possible to reduce the existing liquid, do this: the base is distilled water, and calcium chloride or Epsom salt will help bring it to the level of hardness.

And a little more about water softening options:

1. Boiling. This is a great way to reduce salt levels. Cool the boiling water and collect only the surface 4/5 of the total volume of water. Do not mix layers! The bottom layer will collect all the unnecessary salts, but the water from the surface has the necessary softness.
2. Slightly less effective, but an additive from decoctions is applicable. For example, a decoction of alder cones. Not a very good option, nor is enriching the liquid with peat extract. The biological balance of water can be significantly disrupted, affecting algae growth, fertilization ability and fish spawning.

Although the latter method is somewhat negative, it is necessary to mitigate and stimulate the spawning abilities of characinids.

Reducing or increasing water hardness must be calculated individually, based on the characteristics of keeping fish and plants. Any types and methods are averaged. But with several available medications on hand, you can still provide comfortable conditions for your pets. The main thing is not to forget to clean the bowl; as a rule, any biological changes occur due to the presence of food residues, waste products and dead pieces of plants in the water.

What is aquarium water hardness and how to reduce it

HARDNESS (hD)– due to the presence of soluble calcium and magnesium salts in water. Their concentration in aquarium water is TOTAL HARDNESS, which can be divided into TEMPORARY - CARBONATE and PERMANENT - NON-CARBONATE.

Temporary hardness (KH) is the concentration of calcium and magnesium bicarbonate salts formed from weak, unstable carbonic acid. This hardness can change throughout the day. For example, during the daytime, aquarium plants absorb carbon dioxide, which accumulates in the water, through the process of photosynthesis. If there is not enough carbon dioxide for plants to consume, they will begin to produce it from bicarbonates, as a result of which the temporary hardness of water will decrease.

Constant hardness (GH) is the presence of stable calcium and magnesium salts formed from strong acids - hydrochloric, sulfuric or nitric.

Water hardness is essential to the life of the aquarium world. Firstly, calcium and magnesium salts are used in the construction of the skeleton and affect the construction of the entire fish body. For different types of aquarium fish, water hardness indicators are different and non-compliance with them can lead to a deterioration in the well-being of the fish, to disruption of the reproductive function and fertilization of eggs.

The general hardness of aquarium water is measured in German degrees (hD). 1° hD is 10 mg of calcium oxide in 1 liter of water.

Aquarium water with hardness parameters:

from 1 to 4° hD – considered very soft;

from 4 to 8° hD – considered soft;

from 8 to 12° hD – medium hardness;

from 12 to 30° hD – considered very hard;

Most aquarium fish feel comfortable at a hardness of 3-15° hD.

How to change water hardness:

1.) Increase in rigidity.

The KH hardness can be reduced by adding 1 teaspoon of baking soda per 50 liters, which will increase the readings by 4°dKH.

2 teaspoons of calcium carbonate per 50 liters of water will simultaneously increase KH and GH by 4 degrees.

Another measure to smoothly/gradually increase water hardness is to scatter and decorate the aquarium with seashells.

2.) Reducing hardness (everything is more complicated here):

Use/add distilled water, which is sold in stores;

Use/add rain, snow, melt water from the refrigerator (must be clean, without turbidity or impurities).

Filter the water through an osmotic filter;

Filter the water through peat (peat is added to the filter) or into a container where the water settles;

The hardness of KN is reduced by boiling water in an enamel container for 1 hour, followed by settling for 24 hours;

Natural water softeners are fast-growing plants: elodea, hornwort, nayas, vallisneria.

HOW TO MEASURE the total hardness of water at home without special equipment. equipment and preparations (sample titration with soap solution):

The peculiarity of this method is that 10 mg of calcium oxide in 1 liter of water is neutralized by 0.1 g. clean soap.

1. Take 60-72% laundry soap and crumble it.

2. Water (distilled, snow, melted water from the refrigerator) is poured into a measuring cup (or other measuring vessel) - then distillate.

3. Soap crumbs (counted in grams) are added to the water so that the portion of mala in the resulting solution can be calculated.

4. Pour 0.5 liters of test aquarium water into another bowl and gradually add portions of soap solution (0.1 g each), shake.

First, bluish flakes and quickly disappearing bubbles will appear on the surface of the water. Gradually adding portions of soap solution, wait until all the calcium and magnesium oxide binds - stable soap bubbles with a characteristic rainbow tint appear on the surface of the water.

This ends the experience. Now we count the number of soap portions consumed, multiply them in half (the aquarium water was 0.5 liters, not 1 liter). The resulting number will be the hardness of the aquarium water in degrees. For example, 5 servings of soap*2= 10° hD.

If the experiment is carried out carefully, the error may be +-1° hD.

When a hardness result of more than 12° hD is obtained, the measurement accuracy decreases; it is recommended to carry out the experiment by re-diluting the aquarium water by 50% with distillate, doubling the result obtained.

❶ How to reduce hardness in an aquarium:: Equipment and accessories

In the city water supply, the water hardness level is quite high, so the aquarist often needs to lower it. The inhabitants of the aquarium feel good in water with a hardness level of 3 to 15 degrees. Some types of snails cannot live in soft water because their shells begin to break down. Viviparous fish should be kept in water with rigidity about 10 degrees. For neon fish, water hardness should not exceed 6 degrees. Sagittaria and water fern grow well in water with rigidity 10-14 degrees, and uviranda dies even at 5 degrees.

On the other hand, try to find out what kind of water flows from your tap. This will make your life easier. It is much easier to increase water hardness (for example, for cichlids from Lake Tanganyika), but the opposite is more difficult - you need to filter the water through ion exchange resins, etc. Therefore, consider first whether you can do this for a long time before getting discus if you have artesian water flowing from your tap, which resembles Tanganyika.

1. Don't forget to take into account that water hardness levels vary depending on the season. Many people know that boiling reduces this level well, but this only applies to the temporary component of hardness. In stable seasons - towards the end of summer and towards the end of winter - it increases, and rains and floods lead to softening of the water. Therefore, in spring, fish prepare for spawning and plants begin to grow.

2. Plants such as elodea, chara algae, and hornwort perfectly soften water. Their leaves and stems are usually covered with a crust, which is a precipitate of calcium salts. Plants do not absorb carbon dioxide at night, and during the breathing of living creatures in a reservoir, it accumulates in aquarium, as a result, water hardness increases. If there are sharp fluctuations in the level of hardness at night and during the day due to the presence of a large number of these plants, this can kill all the animals in just one night: they will simply suffocate. That is why the “blooming” of water is a very unpleasant and dangerous phenomenon in aquarium. Be aware that this can start in brightly lit aquariums with rotting food debris. Adding distilled water will help reduce the permanent component of water hardness.

3. In addition to regular boiling, there is another method of obtaining water from rigidity, the level of which is close to zero. To do this, you need to fix a glass plate in front of the spout of the boiling kettle. Place a container on its lower edge to collect condensed vapors. The water obtained in the container in this way will have a hardness close to zero.

4. Water hardness can be reduced by simply freezing it. Fill an empty plastic bottle with 3/4 of water, close it and put it in the freezer. When about half of the water freezes, remove the container from the refrigerator. After this, carefully cut the bottle and remove the frozen part of the water. This piece of ice, when melted, will become water with a very low hardness level.

How to soften the water in an aquarium? Hard water in an aquarium

Water hardness is one of the most common and difficult problems that aquarists have. It has a negative effect on all types of fish, other aquarium inhabitants and aquatic plants. There are several ways to help soften water.

The simplest and most gentle way to mitigate is to plant special plants in the aquarium - for example, hornwort or elody. They are able to reduce the concentration of magnesium and calcium salts, which will lead to the elimination of excessive hardness.

Another method involves using rain or distilled water. Soft water that can be added to the aquarium can be purchased at pet stores, pharmacies or at the bird market. If you decide to use rainwater, you should first clear it of debris and strain it. The amount of water depends on the hardness level, but most often 2 soft ones are added to 1 liter of hard water.

How to soften the water in an aquarium using special devices? Install a membrane in the aquarium, which can be purchased at any pet store. It will help rid the water of harmful impurities; in addition, you can get ion exchange resins, which also soften the water.

If you are filling the aquarium for the first time, do not fill it with tap water right away - let it sit for a few days and then boil it. This method is not recognized by all aquarists, since it can only slightly soften the water. If the water is very hard, then boiling will not bring results.

The most effective method, which many experienced aquarium owners use, is special aquarium chemicals that are sold in pet stores. Thanks to these products, hard water in the aquarium is significantly softened. However, these substances do not have any effect on the fish and plants of the aquarium. They only affect the layers that create increased water hardness.

If you resort to the help of chemicals, then purified water will be no different from ordinary soft water: harmful substances will evaporate.

Each aquarist chooses his own methods of dealing with water hardness: some prefer natural, gentle ones, while others accept only radical chemical ones; the main thing is that this choice is correct and effective, and that all the inhabitants of the aquarium do not experience discomfort. Be sure to monitor the condition of the water in the aquarium and reduce its hardness in time.

How to measure water hardness in an aquarium:: how is water hardness measured:: Animals:: Other

As the first half of the famous proverb says, the fish looks for where it is deeper. But not all representatives of this mysterious world have the opportunity to make at least some choice. In particular, those of them who spend their lives in captivity are often content with the conditions offered to them by the “golden cage” - the aquarium. The most important condition for the normal functioning of aquarium fish is good water.

Question “Why are cats not a product when there are already reviews about them” - 1 answer

On the other hand, try to find out what kind of water flows from your tap. This will make your life easier. It is much easier to increase water hardness (for example, for cichlids from Lake Tanganyika), but the opposite is more difficult - you need to filter the water through ion exchange resins, etc. Therefore, consider first whether you can do this for a long time before getting discus if you have artesian water flowing from your tap, which resembles Tanganyika.

1. The main property is important water – rigidity, the level of which is determined by the presence of calcium and magnesium ions in the liquid, measured in degrees. So, 30° and above is a sign of high rigidity, and 11-18° - medium. Rigidity water measure and control each time you change or top up. As a rule, aquarists use measuring instruments.

2. Take a regular test tube. Pour water into it and add liquid soap drop by drop. Drop - shake the test tube, drop again and shake gently again. The level of hardness is determined by the number of soap drops.

3. Carbonate or temporary rigidity at home can be measured using a pH indicator. Fill a disposable syringe with 1 ml of 70% vinegar essence and dilute 50 ml of distilled or well-boiled water(boil for 20 minutes, then cool and, without stirring, drain the “top” water).

4. Next, in the same 50 ml, but in an aquarium water, drop 8 drops of the indicator, and then, shaking it gently, add the vinegar solution to this water. Its color will begin to change: yellow - light green - with a hint of orange. After this, having measured how much vinegar you spent, multiply the resulting millimeters by two - the resulting number will be carbonate rigidity yu in milliequivalents. Of course, this method is not entirely accurate, because the change in color of the indicator is not clear enough.

5. You can go the other way: simply purchase a test or a special device for measuring “water” hardness at a pet store (though this is not the most “economical” method that exists, but it is relatively accurate). Experienced “keepers” of aquarium fish have corresponding signs (for example, increased rigidity water requires more soap to create foam, “generates” deposits inside the kettle, etc.) You too observe the water before adding it to the aquarium.

6. And now some tips. To reduce rigidity water in your aquarium, add distilled or pure rainwater to it, use special plants, such as elodea and hornwort. In addition, the water can be frozen or boiled well. In the first case, it is poured into a low basin and exposed to the cold. As soon as it freezes to half the container, the ice is broken and, once melted, used for the aquarium. In the second, water is boiled in an enamel cup for an hour, after which it is allowed to cool and two-thirds of the “top” is used. water.

Water is called hard if it contains large amounts of magnesium and calcium salts. This kind of water is usually very disliked in everyday life due to the fact that it forms a layer of scale on teapots and pots and prevents soap from foaming.

You will need

• Methodological publication on analytical chemistry.

On the other hand, try to find out what kind of water flows from your tap. This will make your life easier. It is much easier to increase water hardness (for example, for cichlids from Lake Tanganyika), but the opposite is more difficult - you need to filter the water through ion exchange resins, etc. Therefore, consider first whether you can do this for a long time before getting discus if you have artesian water flowing from your tap, which resembles Tanganyika.

1. Rigidity water There are two types: carbonate (temporary) and non-carbonate (permanent). The first is removed by boiling (about an hour). After this, a white precipitate (calcium carbonate) and carbon dioxide are formed. The second is more difficult to eliminate: either chemically or by distillation. Overall hardness water is determined by the sum of permanent and temporary stiffnesses. In chemistry, hardness is expressed as the sum of milliequivalents of calcium and magnesium ions in 1 liter water. One milliequivalent of hardness is equal to 20.04 milligrams of calcium ions or 12.16 milligrams of magnesium ions per 1 liter water.

2. One way to measure hardness is titration. To carry it out, it is necessary to place 100 ml of the test substance in two conical flasks. water, 5 ml of buffer solution, 1 ml of sodium sulfide and 5-6 drops of black chromogen indicator ET-00 (you must use measuring pipettes). After mixing, the solutions are pink in color.

3. Then the resulting mixture is titrated with Trilon B using a microburette. Trilon B is added carefully, drop by drop, until a blue color is obtained. Next, it is noted how many ml of Trilon B were used for titration, accurate to hundredths. Two samples are titrated for the purity of the experiment.

4. The next step is to calculate the average volume using the simple formula Vav=(V1+V2)/2, where V1 is the volume of Trilon B used to titrate the solution in the first flask, ml, V2 is the volume of Trilon B used to titrate the solution in the second flask. And the last thing to do in this method is to calculate the hardness using the formula F = (Vav*N*1000)/V, where Vav is the average volume of Trilon B used for titration in two flasks, ml (calculated using the above formula), N - normal concentration of Trilon B, 1000 - conversion to 1 l water, V - volume of the studied water, ml. If it is necessary to express the hardness in degrees, then the resulting number should be multiplied by a factor of 2.8.

5. With a hardness of up to 4 mg-eq/l, water is considered soft, from 4 to 8 mg-eq/l of medium hardness, from 8 to 12 mg-eq/l of hardness and over 12 mg-eq/l of especially hard water. Of course, in the conditions of a modern laboratory, the rigidity water can be measured not only by titration, but also by various instruments, for example, a conductivity meter and electronic devices. If it is possible to work on such equipment, then it is simpler, more efficient and more accurate. But the titration method is also quite accurate and simple.

Video on the topic

Video on the topic

How to increase water hardness in a freshwater aquarium?

Aquarium water. Water hardness (dH) http://www.ekzotika.com/aqua34
....In an aquarium containing fish and shellfish, the water hardness gradually decreases: calcium is spent on building shellfish shells, it is absorbed by fish and plants. In an empty aquarium, water hardness increases due to constant evaporation of water, as well as when calcium passes into the water from the soil. Plants such as hornwort and elodea can be used to soften water. To increase hardness, you can add small pieces of limestone, chalk, marble chips, shells, magnesium and calcium chloride to the water. Overall hardness (dH - from the English expression "Degrees of Hardeness" - "degrees of hardness") Measure the dH level. There are commercially available preparations that allow you to quickly determine the total and temporary hardness (KH) of water. To do this, pour the amount of water specified in the instructions into the burette and drop the drug into it drop by drop, shaking the burette slightly after each drop. The number of drops used to obtain the color of the water, the color of which is indicated in the instructions, corresponds to the degrees of hardness.

On aquarium websites, everything is hyped beyond belief. Pre-revolutionary methods and modern ones are described, with all the chemical formulas laid out. Just go to the search and type as the question is formulated. In general, 2 tablespoons of baking soda for every 100 liters. water. Ph will not rise above 8.2. When changing water in the future, add 0.5-0.7 teaspoon per bucket of water. To avoid a sharp increase in hardness, add the solution gradually in several doses.

Alex

Soda has no effect on water hardness! Hardness is the sum of divalent ions, mainly calcium and magnesium. The simplest way is to place a shell or a sprig of coral in the aquarium. You can pour marble or dolomite chips into the filter. Hardness will increase to saturation and will continue to increase due to the dissolution of carbonates by organic acids. In most cases, nothing more is needed. If you want to adjust the hardness up to a degree, you need to buy a hardness meter with an ion-selective electrode (very expensive) or a test indicator - very cheap. And then add the pK agent and measure.

How to recognize water hardness in an aquarium?

Dimka Miller

There are several methods for determining water hardness. To do this, you can buy drugs in specialized stores that allow you to quickly determine the permanent and temporary hardness of water. According to the instructions for these drugs, a certain amount of water is poured into a burette and the drug is dropped into it drop by drop, shaking the burette after each drop. The number of drops used to obtain the color of water indicated in the instructions corresponds to the degrees of hardness.
Water hardness can be determined by the soap method, based on the fact that 10 mg of calcium oxide in 1 liter of water is neutralized by 0.1 g of soap. To do this, 2-3 g of laundry soap are diluted in warm distilled water. This solution is then poured into a graduated vessel. Pour 0.1 g of soap solution into 1 liter of aquarium water until soap bubbles with a rainbow tint appear on the surface. The number of 0.1 g servings is equal to the number of degrees of water hardness. With very hard water, to increase the measurement accuracy, the water is diluted by half with distilled water, and the measurement result is multiplied by 2. For most aquarium fish and plants, water with a hardness of 3 to 16°C can be considered the most acceptable.
For keeping and breeding aquarium fish, tap water is not soft enough; it must be softened. The main method of softening water is to mix it in certain proportions with distilled or rain water.
Or mix tap water with softer, purified water. Before mixing, tap water is heated to 90° C for 40 minutes and then cooled.
Hardness can be reduced by boiling water for 1 hour, then cool the water and use 2/3 of the top layer of water, but this will result in the loss of some of the nutrients needed by plants.
You can reduce the hardness of water several times by simply freezing it. To do this, you need to pour water into a low plastic container (the container is not completely filled, since water expands when freezing) and place it in the freezer. After the water freezes by about half, remove the container from the freezer and keep it warm for some time so that you can easily remove a piece of ice. The remaining salt-rich water is drained, a piece of ice is placed in a clean bowl, melted, the resulting soft water is brought to the desired temperature, after which it can be used for its intended purpose.
The hardness of water in an aquarium containing fish and shellfish gradually decreases naturally: calcium is used by the shellfish to build their shells, and it is absorbed by plants and crabs.
If the substrate is coarse sand and river pebbles, the aquarium water will have a more or less constant hardness. Aquarium plants such as elodea and hornwort are used to soften water.
There are special softener devices that operate on the basis of ion-exchange acrylic resins. In this case, the water with pieces of acrylic resin added to it should stand for 1-3 weeks. After this, it is drained through a hose into the aquarium, leaving a small layer of water at the bottom of the settling vessel.
You can increase the hardness of water by boiling it for 1 hour and use the bottom layer after cooling. You can increase the hardness of water by mixing it with harder water.

Andrey

If you are not going to breed very delicate fish (such as discus or angelfish), then water hardness is not that important for most fish. They have already been living in the water of the area where you bought them for the hundredth generation. But look at the heater. Or evaporate a couple of grams in a test tube. If there is scale there, it means the water is hard. In any case, the water evaporates and the hardness of the remaining water increases. In any case, you will have to add water from the tap (after settling, of course). So trying to maintain a strictly defined rigidity is useless.

pH measurement
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The health of its inhabitants directly depends on what kind of water is used for the aquarium. Water has a huge number of different properties. Therefore, before preparing water, aquarists need to learn how to identify them, as well as control and properly regulate them so that the inhabitants of their home pond feel comfortable staying in it.

The easiest way is to get water from the tap. Plastic drinking water containers, which are sold in stores, are ideal for storing and settling aquarium water. Having collected water in a container, we leave it to settle for a maximum of a week and a half, a minimum of three days. This is done so that the chlorine and other harmful chemical components present in tap water evaporate. The container must be shaken periodically to help the chlorine evaporate; there should be no bubbles on the walls by the end of settling.

Fish should not be introduced into fresh water. The well water is too hard.

pH measurement
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Tap water contains chlorine and other compounds that are harmful to aquarium fish.

Any changes in water parameters must be smooth. If you need to change the water temperature, then no more than 3 ° C per hour. If there is a water change, then no more than a third of the total volume.

If you pour water into a container, even if it is settled, you will not yet create a biological sphere that is comfortable for the fish. Moreover, being released into such a sterile environment, many inhabitants may die from shock. First you need to place the soil, plant the plants and only after a week introduce the first fish. But even at this time it cannot yet be said that the hydrobiological environment has been fully formed.

Aquarium water hardness

Hardness measurement
photo can be enlarged

It is considered the second most important water parameter after acidity. The possibility of keeping and breeding fish and fish depends on it. It affects other properties of water. This parameter is determined by the presence of certain minerals that are dissolved in water.

The overall stiffness consists of two parts:

Constant (GH). It is paramount, as it determines the softness or hardness of the water and the degree of its suitability for the inhabitants of the aquarium. GH determines the concentration of Ca++ and Mg++ ions in water. Boiling leads to the destruction of bicarbonates and precipitation of calcium and magnesium. The hardness that remains after boiling is called constant. It is measured in degrees of hardness.

And all tests are released in them.

Variable or carbonate (KH). It is determined by the concentration of carbonates CO3- and bicarbonates HCO3- in water.

The importance of water hardness in the life of the inhabitants of a home pond is great: magnesium and calcium salts are involved in the construction of the skeleton and skeletal system of fish, and they ensure the hardness of the shell or shell, hardness contributes to the normal functioning and development of the genital organs, it affects the success of the growth and development of plants.
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Water hardness for an aquarium is classified as follows: 0-4 - very soft, 5-8 - soft, 9-16 - medium hard, 17-32 - hard, 33 or more - very hard. Tap water, as a rule, has a hardness of no more than 20. The hardness of water in an aquarium must be within certain limits, usually this range is 3-15 degrees.

The most accessible way to measure the hardness of water for an aquarium is test strips. They have been specially developed for measuring water hardness in aquariums. Simple and easy to use. There is an option where a reagent is added to the specified volume of water and the hardness is judged by the changed color. All calculations are made according to the instructions included in the kit.

To increase the hardness of water for an aquarium, you can place pieces of shells, marble or limestone rocks into the aquarium to increase the overall hardness by 2-4 degrees. The disadvantage of this method is the inability to control the level of rigidity. It is more preferable to filter the aquarium water through a layer of crushed marble, decreasing or increasing the amount of water passing through the filter.

You can also add baking soda in the amount of 1 teaspoon per 50 liters of water to increase variable hardness (KH) by 4 degrees.

To reduce the hardness of the water in the aquarium, you need to add distilled, melted or clean rainwater to it. You can also boil water, cool it without stirring, and drain 2/3 of it from the surface. Add this top water to the aquarium.

Aquarium water acidity

Acidity (pH) depends on the level of hydrogen cations and hydroxide anions in water.

The acidity of tap water is approximately 7. Acidity depends on temperature, and a value of 7 at a temperature of not 25 ° C is no longer an indicator of neutral water. Also, acidity changes throughout the day. At night, carbon dioxide accumulates, and by morning the acidity of the water in the aquarium decreases. During the day, plants actively consume carbon dioxide, so in the evening the acidity level increases. Changes in acidity depend on the hardness of the water: in harder water the changes are smaller.

Acidity can be increased by increased round-the-clock aeration, and decreased by adding corals, shells and other materials containing calcium to the aquarium. You can measure the acidity level with an electronic pH meter or the old old-fashioned method - using indicator paper.

Aquarium water temperature

Heat-loving fish include fish that live in water whose temperature does not drop below 18 degrees. Cold-loving fish are individuals that easily adapt to low temperatures.

They can easily live in an aquarium, the temperature in which will not exceed 14 degrees. Keeping cold-loving fish is only possible in large and spacious aquariums.

It is noteworthy that if heat-loving fish are placed in cold water, they practically stop swimming. This indicates that significant harm has been caused to their health.

Cloudy water in the aquarium
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Muddy water

Cloudy water in an aquarium is a common problem that even experienced aquarists sometimes encounter. It can be fatal to your fish. To avoid this, you need to understand the causes of this disaster and eliminate them.

When creating a new aquarium, within a few days, a huge number of bacteria multiply excessively in the water. This leads to its clouding. This process is completely normal and natural. Before introducing your fish into an aquarium with new water, you just need to wait a few days until it clears itself. Due to lack of food, most bacteria will die out, and the biological balance of the water will normalize. In this case, changing the water is strictly prohibited, because it will also become cloudy.

It is best to add some water from an old aquarium, where the balance has long been established. If this is not the case, it’s okay, the balance in the water will settle itself, it will just take more time.

Another cause of cloudy water could be fish. Excess food that your pets do not have time to eat sinks to the bottom and begins to rot. As a result, the water begins to deteriorate. In such an environment, the inhabitants of the aquarium cannot feel good, and a long stay in bad water will kill them.
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First you need to determine the cause of cloudy water. If it involves overpopulation of the aquarium, it means that it should be strengthened or some fish should be moved to another place. If the reason is the accumulation of excess food at the bottom, then you need to reduce the dose of food or purchase ones that will eat up the settled food. If there is a problem, you need to darken the aquarium or increase the light. To prevent the rapid growth of algae, it is recommended to introduce fish or snails that eat plants. In order to maintain biological balance in the aquarium, it is necessary to have a good filter that matches the size of the water container.

Changing the water plays an important role in maintaining balance in the water.