PURPOSE OF THE DETERMINATION OF WATER PARAMETERS

The exact determination of certain water parameters, such as pH-value, nitrite level and carbonate hardness, allows a detailed analysis of the quality of your pond water. Consequently, unfavourable living conditions for animals and plants are quickly and easily determined, and specific counter­measures may be implemented. "A stitch in time saves nine."

a) The pH-value
The pH-value is an indicator of the concentration of acids and bases in the water. The biochemical equilibrium in a pond, which in turn affects the water quality, is a factor of the pH-value. Great fluctuations in pH-value can be stressful for both fish and micro-organisms. The consequence can be the extinction of certain species of bacteria responsible for the decomposition of harmful substances. An example of such an insufficient breakdown of substances in the water is the transformation of nitrate into nitrite, the latter being toxic to fish. Fluctuations in pH-value in the course of the day are a result of the photosynthesis and respiratory processes of plants and algae (day-night-variation in pH-value). Should these fluctuations exceed one pH-unit, prompt action to increase the buffer capacity is necessary.

If the pH-value is too high, the plants lack nutrients, while the fish may become infested with parasites. In an environment where bases predominate, ammonium is trans­formed into toxic ammonia, which can cause disease or lead to the death of the fish. If, on the other hand, the pH-value is too low, this is often linked to very high concentrations of heavy metals and carbonic acid, which have a detrimental effect on the pond life. In order to offer your fish a habitat with optimal living conditions, we recommend regularly testing the pH-value. For the pH-value of your water to be favourable to the fish, it should be slightly alkaline (i.e. between pH 7.5 and 8.5).

b) The KH-value
The carbonate hardness [KH] of the pond water stabilizes the previously adjusted pH-value. It is an indicator of the water's capacity to regulate harmful acids and bases. In order to protect your fish from the potentially detrimental effects of an acidic or basic environment, a regular KH-check is recommended. Your pond plants will also benefit from a well-balanced level of carbonate hardness.
The KH-value, i.e. the carbonate hardness, reflects the quantity of calcium and/or magnesium ions forming a chemical compound with hydrogen carbonate (HCO3-). In freshwater the KH-value determines the buffer capacity and can therefore be considered its equivalent. The carbonate buffer system is the most important buffer system in water, as well as in the blood and tissue of fish. A small part of the carbon dioxide dissolved in water is transformed into carbonic acid, which lowers the pH-value. The presence of calcium triggers the formation of calcium hydrogen carbonate (KH). If the pond lacks carbon dioxide, the carbonic acid component decreases while the pH-value increases.
Calcium hydrogen carbonate (carbonate hardness) is thus transformed into insoluble chalk and carbonic acid. This process is called "biogenic decalcification" and prevents an increase in pH-value.
The pH-value of insufficiently buffered water fluctuates significantly, putting considerable strain on the fish and the microorganisms that break down harmful substances. This may even lead to the extinction of sensitive species. Another side effect of pH-value fluctuations is the formation of toxic substances, such as ammonia and nitrite. The higher the water's buffer capacity, the higher its resistance to irregularities.

c) Nitrite
Nitrite is highly toxic for all aquatic organisms. Even very low concentrations of nitrite can harm and poison the fish and lead to their death. Although less toxic than ammonia, a nitrite concentration of only 0.1 – 0.2 mg/l is sufficient to harm your fish permanently or even kill them. In combination with decreasing pH- and chlorine levels, the toxicity of the nitrite increases even further. “Gasping for breath” in combination with heavy breathing, or hectic movement without any apparent reason are symptoms of fish poisoning through nitrite. Nitrite is a by-product of the decomposition process of organic matter into nitrate. Biological irregularities, malfunctioning filters, or local centres of decomposition in the pond bed can cause an increase in nitrite.
If the nitrite content is permanently higher than 0.3 mg/l, the water quality is greatly diminished. In this case, products containing special bacteria, e.g. ClearLake, should be used in order to break down the nitrogen. It is particularly important to check the water's nitrite concentration on a regular basis. This way, immediate countermeasures can be taken if and when necessary.

CONTENT

• pH-test for the exact determination of the pH-value: pH-indicators 1 to 6, re-sealable test tube
• KH-test for the determination of the carbonate hardness, acid and alkaline concentrations:
  KH-indicators 1 and 2, KH-test solution, re-sealable test tube, measuring syringe
• Nitrite test for the determination of the nitrite levels: nitrite reagents 1 – 3, nitrite test solution, re-sealable test tube (see KH-test), measuring syringe (see KH-test), spatula
• Detailed instructions