home Aquarium How To Increase The Hardness Of The Water In An Aquarium

How To Increase The Hardness Of The Water In An Aquarium

Table of Contents

Optimum stiffness values

Different aquatic organisms and plants require water with certain, differing values ​​of the hardness index. For example, fish from the haracin family do best in very soft water, and some African cichlids, on the contrary, in very hard water. When purchasing plants, fish, snails and shrimps, you should always first evaluate the possibility of their further coexistence. the physical and chemical parameters of your aquarium water should be suitable for them.

How to increase water hardness?

A small increase in the hardness of the water in the aquarium can be achieved by placing pieces of marble or shells in the water. In this case, it does not rise immediately. Note that the softer the water, the faster its hardness increases.

A faster method is to add calcium chloride and magnesium sulfate (magnesia) solutions sold in pharmacies. So the addition of 1 milligram of a 10% solution of calcium chloride increases the hardness of 1 liter of water by about 3 °, and 1 milligram of a 25% solution of magnesium sulfate will increase the hardness by 4 °. The simultaneous use of calcium chloride and magnesia will give a closer to the natural ratio of calcium and magnesium ions in the aquarium water.

Water hardness in an aquarium: how to increase and how to decrease

How To Increase The Hardness Of The Water In An Aquarium

Water hardness is the proportion of mineral salts it contains, usually calcium and magnesium salts. Determine the total, or carbonate, hardness, and constant, or non-carbonate. Total hardness is the sum of temporary and permanent hardness. The unit of measurement is degrees. In domestic sources for aquaristics, German degrees of hardness dH are used. Very soft water is water with hardness from 0 to 4 °, soft. from 5 to 8 °, medium hardness. from 9 to 16 °, hard. from 16 to 30 ° and over 30 °. very hard. Typically, aquarists use tap water, the hardness of which is variable and is determined by the season, rainfall and geography of the place of residence. For example, water hardness is from 4 to 12 °, 2-3 ° in St. Petersburg, 12 ° and higher in Odessa.

What is redox potential?

Redox potential, or redox potential, is a characteristic of the chemical and biological activity of water. In an aquarium, it has significance as a characteristic of the saturation of water with organic matter, that is, the pollution of the aquarium. The redox potential is measured using a special electronic device. a pH meter. Redox potential is defined in arbitrary units from 0 to 42. It is usually impossible to measure it at home.

In a newly equipped aquarium, it has a size of 30. 34. At the same time, most of the floating in the water column, as well as small-leaved plants with a weak root system (peristolis, hygrophila, kabomba, etc.) develop well. This may indicate a high value of the redox potential. Further, the value of the redox potential decreases little by little. An indicator of this is the good growth of Echinodorus and Aponogetons. In an older aquarium, when the redox potential is even lower, Cryptocorynes thrive. When cryptocorynes also begin to develop worse, it means it’s time to clean the soil, partially replace the water. It may be necessary to improve filtration by installing a bottom filter.

How to change water hardness

It is always easier to increase the hardness of the water than to lower it. There are many ways to increase water hardness. Let’s consider the main ones:

  • Using aquarium soil based on shell rock, limestone or marble;
  • Adding a solution of magnesium sulfate (magnesia) to the aquarium, while 1 ml of a 25% aqueous solution per 1 liter of water increases the hardness indicator by 4 German degrees;
  • Adding one teaspoon of calcium carbonate to 50 liters of water increases the hardness by 2 German degrees;
  • Adding a teaspoon of baking soda (sodium bicarbonate) to 50 liters of water raises its hardness by 4 German degrees.

The easiest way to reduce hardness is to add distilled water, melt water, rainwater, or water obtained after passing through a reverse osmosis filter into the aquarium. Bring the water hardness in your aquarium to optimal values ​​and control it periodically, its inhabitants will be grateful to you for this!

Permanent and temporary stiffness. What it is?

The constant or non-carbonate hardness of water depends on the sulfates, calcium and magnesium chlorides, and dissolved in water. This can only be eliminated by distillation of water or by chemical means. While the temporary or carbonate hardness is determined by the m calcium and magnesium bicarbonates.

How to prepare peat extract?

To prepare the peat extract, several pieces of peat are boiled in an enamel bowl. The amount of peat and the volume of water in which it will be digested does not matter. Then, after cooling, filter the resulting broth through cotton wool 2-3 times. Peat infusion is prepared in the same way as a decoction, but the peat is not boiled, but insisted. For every 100 liters of water, 0.5-1 liters of broth or infusion should be added. To match local peat with tropical peat, some hobbyists add a few grains of coffee, a pinch of tea, a eucalyptus leaf, as well as a few alder cones and some oak bark.

Water hardness analysis

Quite accurately measure the value of water hardness in German degrees allow drip tests. reagent kits. Well-known companies produce such tests especially for aquarists. Typically, the test consists of a volumetric tube and a reagent dropper. A certain amount of water from the aquarium is taken into a test tube, after which the reagent is added dropwise and with constant shaking. The hardness value is usually equal to the number of drops of the reagent after which the solution in the test tube changes color.

Rapid tests are also issued, when water hardness is determined by comparing the color of a strip of indicator paper moistened with water from an aquarium with the colors of a reference scale. You can estimate the hardness of water using an express test rather quickly, but the accuracy of such a measurement is low.

What is ppm?

Salinity, or mineralization, of water is expressed by the amount of salts dissolved in it. Their concentration in grams per 1 liter is called ppm (° /%).

Water hardness in an aquarium: how to increase or decrease, what you need to know about it

The hardness of the water in an aquarium is one of the most important conditions for the creation and functioning of an aquarium ecosystem. Without establishing the required indicators of living organisms in the reservoir, it is impossible. The knowledge gained, as well as a share of patience, will allow you to achieve the desired concentration of Ca and Mg salts at home and admire healthy fish and dense green plants.

How to increase the hardness of your aquarium water

If the tests carried out reveal values ​​that do not correspond to the required ones, you can adjust the hardness to the desired value. However, there should be no abrupt change in values, this can cause stress in fish.

If you need to increase the level of hardness, the following methods are used:

  • Add the bottom layer of boiled liquid rich in salts.
  • Mix water with harder.
  • Add coral or dolomite chips to the aquarium filter.
  • Place marble, limestone containing calcium carbonate or colored glass on the bottom. You can dissolve pieces of chalk by increasing the level by 2-4 °. The disadvantage of this method is the difficulty of controlling the rigidity. Better to pass the liquid through a filter with the addition of marble chips.
  • Decorate the bottom of the aquarium with shells.
  • Add calcium carbonate 2 tsp. For 50 l.
  • Use dissolved baking soda, 1 tsp. For 50 liters, or 0.2-5 g per liter. This method is suitable for water with an indicator of at least 8 °.
  • Add a 10% solution of calcium chloride and magnesium sulfate: dilute 50 g, obtaining a volume of 750 ml. Use 1mg per liter each.
  • Pour 1 ml of 25% magnesium per 1 liter of water.

Almost all of the above methods change the stiffness indicator by 4 °.

Normal and critical stiffness indicators

The life span of the inhabitants depends on the hardness of the water in the aquarium. The alkaline earth metal salts of magnesium and calcium, for example, affect growth rates, the formation of fish bones and shells in molluscs. They also act as a mineral fertilizer for plant development. In a too soft environment, leaves curl and shoots die.

READ  How to Age a Fish


Mg-eq / l

Normal kH is in the range of 4-8 °. In older aquariums, the reading drops below this mark over time due to water oxidation.

Some species need a mild environment, while others, on the contrary, prefer higher degrees. This must be taken into account in several cases:

  • At the initial formation of the aquarium: for snails, more rigid is preferable, for neon fish 6-8 °, for guppies 5-10 °, scalar 18 °, for ferns 10-14 °.
  • With a complete replacement of the liquid and transplanting fish into it.
  • Water preparation for spawning. Some species reproduce in all conditions, for others, you must first prepare a liquid.

For most aquarium fish, values ​​from 3-15 ° will be the norm. A value below three indicates a lack of rigidity.

With a TDS meter

Compact instrument for measuring salt concentration. To check, immerse the device in liquid and wait, the result will be shown in milligrams per liter. Service life 1-2 years. However, the measurement can be considered relative, since, in addition to calcium and magnesium, the final number will contain a small amount of impurities of other substances.

Using laundry soap

It is considered the most affordable way. Needed: 1 gr. Crushed soap (60 or 72%) and heated distilled water. A solution is made from them and added to a jar, where 0.5 liters of tap water is poured. After the appearance of a cap of foam. a signal that the salts in the liquid are bound. the remaining soap solution is measured with a ruler. This value is subtracted from the original amount. Each centimeter obtained by subtraction is equal to 2 degrees of hardness. Find out the result from the table.

The average tap water value is 20 °, which is the upper limit for many fish species.

General definitions

Dirty and cloudy liquid spoils the overall look, but crystal clear is also not always useful. After acidity, the second most important parameter is the level of hardness. Its values ​​that are too high or too low will primarily affect plants.

Rigidity is divided into 3 types:

  • Total (gH). Consists of two values ​​given below.
  • Non-carbonate. This is a constant value of the level of chlorides and sulfates of magnesium and calcium dissolved in the liquid. Does not change when boiled at home. However, it can fluctuate within 24 hours. This is facilitated by the presence of plants or the time of day.
  • Carbonate (kH). Concentration of bicarbonate salts (Mg and Ca). At a pH of more than 8.3 and boiling, they form a flocculent precipitate, settle as crystals on the walls of the container and a film on the surface of the water.

Photo gallery of tools for measuring water hardness:

Kh. most important for aquarists, this is due to several aspects at once:

  • The level of carbon dioxide that is produced when fish breathe. At high kH, the CO2 value can reach a critical level of over 30 mg / l, which will lead to the death of the inhabitants. However, a low concentration below 15 mg / l will not allow plants to develop normally.
  • PH stabilization. There is a direct relationship between two values.
  • Water for spawning of some fish species. It is a liquid with low kH and acidity in the range of 5.0-7.0.

Mr. Tail recommends: methods for determining stiffness

To find out the value of tap water, use several methods.

Chemical reagent Trilon “B”

This method is considered the most accurate, the disadvantages are the complexity and duration of the experiment. A buffer mixture, a chemical reagent and a special indicator are added to the water taken from the aquarium. As the reaction proceeds, the color of the solution changes from cherry to blue-green.

Strips with reagents applied to them

How to increase the hardness of your aquarium water naturally

Water hardness decreases over time in the aquarium. The reason is the processes of decay of organic matter, softening of water due to the installed driftwood or the replacement of water with a lower hardness.

  • Branded chemical additives are expensive
  • Hardness changes quite dramatically

A sharp change in hardness is fatal for many fish, which will inevitably occur if the dosage is violated. And the best choice would be to maintain stiffness naturally.

Increasing pH with increasing hardness

Typically, an increase in the carbonate hardness of the water will increase the pH level. This is due to the fact that calcium and magnesium carbonates affect both parameters at once. In rare cases, you will encounter high aquarium water hardness at low pH levels. This is due to the presence of sodium and potassium carbonates, which raise the pH but do not affect hardness in the absence of calcium and magnesium carbonates.

In other words, as the water hardness rises, the pH level rises. This happens if the current pH level is determined by calcium and magnesium, which is observed in the vast majority of cases.

To smoothly increase water hardness in a natural way, there are several simple and affordable ways:

  • Shredded corals
  • Dolomite chips
  • Limestone
  • Soda

The disadvantage of using is the impossibility of calculating the final water hardness. After the water hardness is fixed at one value, it will no longer change, always remaining at the same level.

Shredded corals

Coral skeletons and most clam shells contain high amounts of calcium carbonate. Therefore, coral chips are made from them, which are packed in small permeable bags.

Add a bag to the inside of the aquarium filter and after a couple of hours the water will begin to rise in hardness. The rate of rise, as well as the final hardness, is controlled by adding or reducing the amount of coral chips.

Dolomite chips

Dolomite crumbs are used to raise the carbonate hardness of the aquarium water. Dolomite, like coral chips, is poured into the aquarium filter, which increases the water hardness, but makes it difficult to rinse the filter.


Limestone contains high amounts of calcium carbonate and is ideal for raising and maintaining water hardness. A large piece of limestone decorates the aquarium, mimicking a limestone reef from the wild.

Several types of limestone are used in aquariums: oolite, tuff, dolomite, travertine, aragonite. There is no difference in their use when it comes to water hardness. Add the amount of limestone to achieve the desired hardness level.

By adding a soda solution, the carbonate hardness of the water can be quickly increased. Add 1 teaspoon of baking soda to 100 liters of aquarium water after dissolving the baking soda in a glass of water. Pour the prepared solution into a place with strong current. This will increase the carbonate hardness by 2 degrees.

When increasing the hardness, do not be lazy to check the current value, as extremely hard water is deadly for fish and plants.

What is water hardness

Before settling a home reservoir with fish, crustaceans, plants, you need to assess the possibility of their coexistence. The chemical boundaries of the habitat for them must be identical. Water hardness is one of the most important parameters, which implies the degree of saturation with dissolved minerals. There are two indicators of stiffness:

  • Constant hardness (GH) is the presence of magnesium and calcium sulfates and chlorides dissolved in the liquid. This indicator determines the degree of suitability of the water for the aquarium. The density of Mg and Ca can be reduced by distillation or by chemical methods. Minerals are needed for the skeletal tissue of fish, are of great importance for the life of underwater flora and fauna.
  • The carbonate hardness (KH) of the aquarium water is determined by the level of carbonates and bicarbonates. This value changes several times per day. During the day, plants, due to the ongoing processes of photosynthesis, take away the carbon dioxide accumulated during the night. When there is not enough carbon, plants begin to synthesize it from bicarbonates.

The carbonate hardness is different for different aquarium inhabitants. Failure to comply with the correct parameter will definitely lead to a deterioration in the well-being of fish and a violation of the ability to reproduce.

How to increase or decrease the hardness of your aquarium water

An artificial biocenosis in an aquarium will not do without human intervention. It is necessary to maintain optimal performance of the aquatic environment. Too warm, cold, acidic or hard water causes discomfort to fish and negatively affects the vegetation of the reservoir. It is important to be able to determine and regulate the degree of water hardness, which has a huge impact on other parameters.

How to reduce the hardness of your aquarium water

Softening the water in the aquarium is more time consuming. One of the following procedures is performed:

  • Add rainwater to the fish tank. When collecting rainwater, its purity must be taken into account as much as possible. You cannot collect water flowing from the roof.
  • Top up with distillate. They buy ready-made or purchase special equipment to do on their own.
  • Boil the liquid, let it settle and pour the top layer into a home reservoir, in which you want to make the water softer.
  • Freeze water in the refrigerator to 50%. The non-frozen part of the liquid is disposed of, the ice is melted and poured into the aquarium.
  • Peat purified by boiling is placed in a bag in a filter container or used as a substrate for plants. Activated carbon is placed in the filter to remove the yellow tint from the water.
  • Hornwort, egropil, elodea, planted in the ground, are able to soften the aquatic environment.

Sometimes aquarists take to soften water where alder cones were boiled. The method is extremely unsuccessful, because the broth dramatically changes all other water parameters.

How to increase the hardness of your aquarium water

To increase the rigidity in the aquarium does not require complex manipulations. The most popular ways:

  • Enrich the soil with marble chips, shells, measuring and increasing the stiffness to the required parameters. Connecting filter systems allows you to regulate the flow of water that passes through the minerals.
  • Place calcium carbonate in the tank. Two teaspoons per 50 liters will raise the dH values ​​by 4 divisions.
  • 25% pharmacy drug of magnesia at the rate of 1 ml per liter of liquid will raise dH by 4 divisions.
READ  How to determine the hardness of the water in an aquarium

To increase the saturation of magnesium and calcium sulfates and chlorides in the tank, the easiest way is to replace partially aquarium water with a harder one.

How to determine the hardness of your aquarium water

There are simple tricks to measure the presence of minerals in water at home:

  • TDS. meter or saline meter refers to simple devices. The principle of operation is based on measuring the degree of electrical conductivity of a liquid. The dH value of the aquarium can be checked approximately.
  • Test. strips. The method is suitable for inexperienced users. Adding a reagent to a certain amount of liquid changes the color of the water. Hardness is determined by color. It is difficult to find strips on sale. When buying, be sure to take the instructions for use.
  • Laundry soap. With it, you can find out the exact parameters. Stir one gram of soap in a regular faceted glass with a little warm distilled water. Top up the distillate for 72% soap at 70 mm, for 60% soap 10 mm lower. Slowly pour the solution in portions into a 1 liter jar of aquarium water. If the reaction proceeds when pouring a 10 mm solution, the hardness level is 2 ℃ dH. If you need to pour out 40 mm, then 8 ℃ dH. The indicator is higher than 12, if the foam did not appear when pouring the entire glass.

Testing with the Trilon B chemical reagent is the most accurate, but overly complex and requires special chemical equipment. The most affordable is soap. The deviations in the test results are insignificant.

Often the results of measuring the stiffness give disappointing results. It is necessary to either increase or decrease the water hardness to the normal level. This should be done gradually so as not to create a stressful situation for aquatic life.

Stiffness standard

The total hardness of an aquatic environment is measured in German degrees: 1 dH equals 10 mg of calcium oxide in a liter of water. The following levels of hardness of the aquatic environment are conventionally distinguished:

  • 0-4.5. very soft.
  • 4.5-11.2. soft. There are not enough minerals in such water.
  • 11.2-22.4. medium hard. Characin, small barbs, catfish corridors feel good.
  • 22.4-33.6. hard. Suitable for African cichlids, cichlases, sagittarius and fern growth. A high concentration of minerals is vital for crustaceans, because shells are gradually destroyed in soft water. Viviparous species of fish live well and leave offspring in such an environment.
  • than 33.6 is very tough. For most aquatic life, such an environment is unsuitable.

There is no single norm. Fish and plants have different preferences. We can talk about critical values ​​that must be excluded when water is being prepared for a domestic reservoir. Hardness should not fall below 6 or rise above 33 degrees.

An aquarist should not relax even when the water looks clear. It is impossible to determine the concentration of minerals and acidity by external signs. Experienced aquarists can do this by observing plant health and fish activity.

In order for the main parameters, including the dH level, to remain normal, sometimes it is enough just to properly care for the home reservoir. It should not be overpopulated and overloaded with plants. It is necessary to ensure constant air exchange and filtration, to do regular water changes. It is easier to bring the aquatic environment to optimal performance once, then periodically monitor it. The inhabitants of the underwater kingdom will definitely love it.

If you liked the article, leave comments and share the link to it in social networks.

How to measure the hardness level

Experienced aquarists know to measure hardness regularly. Deviations or fluctuations in parameters will stress the fish, and may even shorten their lifespan. Determining the hardness of water at home will help such devices and inventions as:

There is also a popular test method that uses laundry soap. It washes hard in very hard water and produces a lot of foam with excess salts.

To check the hardness level in this way, you need to do the following:

  • A bar of laundry soap is crushed to small crumbs with a knife.
  • Soap shavings are gradually poured into warm distilled water, stirred a little. The soap and water mixture should reach 6-7 cm.
  • Water is poured into a large container from the reservoir in the amount of 0.5 liters.
  • The soap mixture is poured into a container. Water from the aquarium is poured into a large container in the amount of 0.5 liters.
  • Count how many cm3 of the soap mixture was poured into the water from the tank and multiply the number by two. For example, if 3 cm was added, then the water hardness is 6C.

Sometimes plants or fish need changes in water hardness. This can be done with the advice of a professional or experienced aquarist below.

Norm of water parameters

For water hardness, the norm is set by the requirements of specific inhabitants of the reservoir. Each specific type of fish and flora requires individual indicators of water, therefore, it is necessary to select residents with similar conditions for settling in a reservoir. Determine the level of water hardness in the aquarium by the number of degrees:

  • 0C to 4C. very soft;
  • 5C to 8C. soft water;
  • 9C to 16C. Medium Hardness;
  • 16C to 30C. hard water;
  • Above 30C. very hard.

Tap water usually reaches 20C, so it is categorically unsuitable for certain types of fish. The level of hardness has a profound effect on the life and development of aquarium inhabitants. Experts have revealed how salt compounds of magnesium and potassium affect the underwater world:

  • Help in the formation of fish bones;
  • Molluscs and crustaceans help to strengthen shells and shells;
  • Improves habitat and creates favorable conditions for reproduction.

Typically, the mineral salt range is typically 3C to 15C, however some species require a high level of hardness. For example, snails. shells fall apart in soft water, so every aquarist should know how to determine the hardness of the water in an aquarium, as well as ways to reduce and increase it.

How to check the water hardness in an aquarium?

When purchasing a home pond, many aquarists first think about the layout of the scenery and the settlement of fish, forgetting about such an important aspect as filling the tank with good water. Typically, the most commonly used aquarium liquid is tap water that does not meet the requirements of fish and vegetation. Disregard for the measurement of indicators is a gross mistake of many novice aquarists, and has a detrimental effect on the condition of underwater inhabitants.

What is water hardness

The hardness of water is the percentage of calcium or magnesium salts in it. It is they that determine the overall (carbonate) hardness or non-constant, measure the hardness in degrees. In the reference books of the USSR, German degrees were previously used. dH.

The water hardness in an aquarium is a secondary indicator after the acid level. A comfortable environment for fish, breeding conditions and vegetation development depend on it. There are two types:

  • Constant or total hardness (GH) is a key indicator that determines the softness or neutrality of water. GH detects the accumulation of ions that precipitate when boiled. Salt level after boiling and is constant hardness.
  • Variable or carbonate water hardness. the percentage of carbonate CO3 and bicarbonate HCO3.

How to increase the hardness of your aquarium water

In some cases, an urgent increase in hardness is required for the comfortable existence of underwater inhabitants. How to increase water hardness:

  • Boil tap water for about an hour. Drain the upper layers of water into the sink, and pour the lower third into the reservoir.
  • Add hard water to the reservoir, gently pouring it in small portions.
  • Place seashells, pieces of marble or limestone chips in the tank. This will help raise the level by 2-4C.
  • Pour 1 hour. A spoonful of baking soda into a pond. this increases the indicator by 4C.
  • Add calcium carbonate (50 g per 50 L). this raises the level by 4C.

When resorting to these methods, one should be careful and careful: the hardness can rise to very high levels, therefore the degree of salt concentration is constantly measured. If the stiffness needs to be increased from a low to a high level, this should be done gradually and smoothly so as not to stress the fish.

How to lower water hardness

Sometimes it is necessary not to increase, but to lower the hardness of the water in the aquarium. This process is much more difficult than increasing the hardness level. Mitigation can be achieved using freezing, boiling, and also using special preparations. There are several ways to reduce the hardness of your aquarium water:

  • Melted or purified rain moisture is added to the reservoir.
  • The flowing liquid is brought to a boil, cooled and the upper layers are poured into the reservoir.
  • Water is placed in the freezer until half of the container turns into ice. Then the frozen part is split, the moisture is drained, and the ice is melted to its original state. The resulting liquid is added to the reservoir.
  • You can reduce the hardness by passing the liquid through special filters.

In addition to using available tools, you can use Trilon-B, strictly following the instructions. Some aquarists advise planting elodea and hornwort in the reservoir. Another method to reduce the hardness of the water is the infusion of alder cones. It is poured into the reservoir in small portions, however, the effect will be insignificant. only 1-2C.

Water hardness is the most important aspect for the favorable life and health of fish, molluscs, algae and plants. It is not worth neglecting the measurements of the salt concentration, because for some inhabitants of the aquarium, even the slightest deviation of 1-2C can become critical. Taking care and paying due attention to the home reservoir, you can get a real piece of underwater depths that will delight both guests and households.

READ  How much water should be infused for the aquarium

How to check performance using laundry soap?

For this experiment, you will need distilled water, laundry soap (60% or 72%), a balance, a ruler, a cylinder-shaped glass, a liter jar or a transparent measuring container.

  • Only 1 g is cut off from a piece of laundry soap and finely chopped. The resulting soap crumb is sent to a glass.
  • Distilled water is heated (but not brought to a boil!), And the soap is poured into a glass with it. just a little bit to dissolve the soap.
  • After that, distilled water is added to the soap solution, based on its concentration: for 60%. 6 cm, for 72%. 7 cm.
  • Cold tap water in a volume of 500 ml is poured into an empty jar. Soapy solution is gradually poured into it with continuous stirring. As a result, a white foam should form, which means that the soap has bound the salts of the liquid.
  • Then you will need a glass of soapy water again: you need to measure the height of the residue. The remaining volume (also in cm) is subtracted from the initial height of the soap solution (in cm). We get a certain number. So, every centimeter of soap solution binds the amount of salts in tap water equal to 2 degrees. That is, if foam appeared after you poured 2 cm of solution into the jar, the liquid indicator is 4 degrees (or 1.5 mEq / l).
  • Then the result is compared with the table and the level of rigidity is determined.

Chemical reagent Trilon “B”

The measuring principle is complex, confusing, long. This will require a whole chemical experiment.

By the amount of Trilon B. the sodium salt of ethylenediaminetetraacetic acid, which looks like an ordinary white powder, it is possible to determine the calcium and magnesium salts dissolved in water.

The change in the color of the indicator also depends on the pH of the water, therefore, auxiliary substances are used. a buffer mixture NH4OH NH4Cl, which maintains a pH of about 10.

For the experiment, you need a conical flask with a volume of 200-250 ml, test water, buffer mixture, Trilon B solution and indicator solution.

  • A solution of Trilon B is made from 9.3 g of the substance and distilled water so that the total output volume is 1 liter.
  • The buffer mixture is prepared by mixing 20 g of ammonium chloride (NH4Cl) and a small amount of distilled water, then add 100 ml of 20% ammonia hydrate (NH4OH) and such an amount of distilled water that the total volume of the solution is 1 liter.
  • The indicator will require 0.5 g of eriochrome black T, 10 ml of buffer solution and ethyl alcohol in such an amount that the solution output is 100 ml.

50 ml of water from the aquarium, 5 ml of the buffer mixture and 10-15 drops of the indicator (until a cherry-red color appears) are poured into the flask. The flask is shaken continuously and titrated with Trilon B solution until the solution turns purple. At this stage, the titration slows down and continues until a blue color with a green tint appears. After that, calculations are made:

X = (v0.051000) / v1, Where

  • X is the amount of calcium and magnesium salts soluble in water, mg-eq / l;
  • V is the used amount of Trilon B;
  • V1. test water volume.

To convert to degrees, the resulting figure is multiplied by 2.8. To determine the hardness of water, a special table of V.P. Datskevich is used, according to which it is easy to find out the desired value, based on fractions of a degree.

The advantage of the method is the accuracy of the study.

  • Long and complicated process;
  • Difficult to find substances;
  • Sometimes Trilon B is sold only in high weight (from 25 kg), and accordingly has a high cost.

How to measure with test strips?

The benefits include:

  • Fast results;
  • Measurement can be carried out directly in the aquarium;
  • Easy availability and cheapness of the test.

The disadvantage is the inaccuracy of the result. The strip acquires a shade that matches the palette, and the hardness is determined by eye. And you will have to translate foreign degrees into Russian ones, because K. The tests use European standards.

How to lower the readings if the liquid is too hard?

How to make the water softer? At very high hardness, the water in the aquarium becomes close to seawater, and freshwater fish cannot live in it.

Also, osmotic pressure makes its contribution, which negatively affects the vital activity of many fish, and at critical rates (over 35-50 degrees) can lead to death.

Reducing water hardness is more difficult than increasing it. However, there are several ways to soften hard water:

  • Mix tap water with distilled or rainwater.
  • Boil water for an hour, cool and pour the top 2/3 into the aquarium.
  • Pour water into a low dish (for example, a basin) and partially freeze. What is left in a liquid state, pour out, and melt the ice and add to the aquarium.
  • Pass water through an osmotic filter or deionize.
  • Pass the water through the peat of the filter, having previously boiled it. Filtration through activated carbon is required for the resulting yellow tint to disappear.

A clear instruction for lowering water hardness is below:

What it is?

Water hardness refers to the salts of alkaline earth metals, which are sometimes called “hardness salts”. these are mainly calcium and magnesium. The hardness index is also influenced by beryllium, barium, strontium, radium and unbinilium. Accordingly, a large amount of dissolved salts make water hard, and a small amount. soft.

For the aquarium ecosystem, hardness is even more important than acidity. Its role can hardly be overestimated:

  • Magnesium and calcium salts are involved in the construction of the skeleton of fish;
  • The strength and hardness of the shell of crustaceans and molluscs depends on their number;
  • The development of the genitals depends on rigidity;
  • Ensures normal plant growth and absorption of nutrients.

The optimal level of water hardness in the aquarium should approximately correspond to the same indicator of the natural habitats of each specific species.

Distinguish between general hardness, carbonate and non-carbonate.

Total (gH)

Total hardness (gH) is the total amount of calcium and magnesium salts dissolved in water. In it, carbonate (temporary, soluble) and non-carbonate (permanent, insoluble) hardness are distinguished. Essentially, total hardness is a combination of soluble and insoluble hardness.

How to know whether to decrease or increase the water hardness in your aquarium?

An aquarium is an artificial biocenosis, in which it is imperative to maintain optimal conditions. This is done primarily for the comfort and health of its inhabitants.

It is important to take into account the temperature and purity of the water, the level of lighting, observe the feeding and aeration regime. An equally important factor is the level of water hardness.

After reading the article, you will learn how to reduce or increase the level of stiffness, and you can also measure the indicators yourself at home.

Carbonate (kH)

Carbonate hardness (kH) is characterized by the presence of bicarbonate and bicarbonate anions in water. This indicator is also called the alkalinity of water.

A distinctive feature of carbonate hardness is that carbonates precipitate. In ordinary life, we see it in the form, for example, of scale in a teapot.

When boiling water, carbon dioxide, water and calcium carbonate are formed, which precipitate. This reduces the hardness of the water. The same reaction occurs if the pH8.3. Therefore, carbonate hardness is also called temporary: it can be eliminated by boiling.

Its level is usually lower than the total hardness, however, if you decrease kH, then gH also decreases. Therefore, kH is considered one of the most important indicators of water in an aquarium.

The fact is that if a little acid is added to alkaline water (with a high kH index), nothing will happen: the acid is simply neutralized, and the kH will decrease. In the opposite situation, if acid is added to water with a low carbonate hardness, then the alkalinity of the water will drop to a critical level at which living organisms can die.

How to increase the level and make the liquid harder?

Increasing the rigidity in the aquarium is necessary if its inhabitants require mineralization. For example, some plants, crustaceans, and molluscs cannot thrive without adequate calcium.

How do I increase the level? There are several ways to increase the hardness of the aquarium water:

  • Mix aquarium water with harder water from another source. It is important to respect the proportions and not overdo it, i.e. Pour in water gradually, periodically repeating the study.
  • Boil water in an enamel bowl for about 60 minutes, then carefully pour 2/3 of the top. Gently pour the bottom remaining part into the aquarium.
  • Add shells, marble and other limestone rocks to the aquarium. The disadvantage of this method is that the hardness cannot be controlled. Therefore, you can use shells as a filter for aquarium water.
  • 1 tsp L. Baking soda in 50 liters of water helps to increase kH by 4 degrees.
  • 2 tsp L. Calcium carbonate by the same volume increase gH and kH by 4 degrees.
  • Add 1 ml of 10% calcium chloride and 1 ml of magnesium sulfate to 1 liter of water. Hardness will increase by 4 degrees.
  • Pour magnesium in a 25% solution (1 ml per 1 liter of water). This will increase the hardness by 4 degrees.

Another way to increase water hardness can be found below: