PH/KH Minus from Tetra and similar products consist of diluted hydrochloric, sulfuric or phosphate acid. They lower the pH value and the carbonate hardness KH.
Such acids are sold under various names in the aquarium trade. Popular terms such as B. oak extract, which give the impression that they are harmless natural products. The use of such acids in aquaristics is controversial and can result in undesirable side effects. phosphate-containing agents e.g. B. increase the phosphate value and this can result in increased algae growth.
Arguments for PH/KH minus:
- Chemical agents are suitable for the production of special water, e.g. B. for fish farming.
- Plant fertilizers are also chemicals.
- Mistakes can also be made using other methods, e.g. B. too much pH reduction, too much carbon dioxide, etc.
- The change in the water through osmosis systems, ion exchangers, carbon dioxide, plant fertilizers, etc. is also an intervention in the chemistry of the water.
- Aquarists can usually only observe a few water values. These are: temperature, pH value, CO2 content, carbonate hardness, total hardness, nitrate, nitrite, conductivity, phosphate, iron and copper. If these water values are suitable for the fish being cared for, the water is suitable for these fish. Statements about other water values and about the effect of agents such as PH/KH Minus on them are pure speculation.
Arguments against PH/KH minus:
- As little chemicals as possible should be used in the aquarium.
- The use of such means requires specialist knowledge.
- In complex systems such as aquariums, unpredictable side effects can occur.
- Plant fertilizers and pH-lowering agents cannot be compared.
- Plant fertilizer consists of harmless chemicals, plant minerals and trace elements that pose no risk.
- Plant fertilizer does not contain hydrochloric acid.
- The pH can be lowered more safely with carbon dioxide, alder cones, peat, tea leaves or other means.
- Osmosis systems or ion exchangers are more suitable for long-term lowering of the pH value and carbonate hardness.
- The composition of the agent is not declared and therefore unknown.
- Tap water is overloaded with various substances, making it impossible to produce tropical water. Adding other substances to the aquarium will only make this condition worse.
- If you want to make targeted changes to the water, use agents whose content, effect and side effects are known.
- It is not enough to change the carbonate hardness and the pH value. The total hardness must also be changed.
Conclusion
Means such as PH/KH Minus must not be used indiscriminately. The user must be aware of the mode of action and side effects of these drugs. Use can be useful for certain areas of application. Ultimately, however, it also depends on one’s personal attitude whether one regards such substances as undesirable or as helpful chemistry.
alternatives
Cheaper chemical agents as alternatives are the use of hydrochloric, sulfuric or phosphoric acid. For small aquariums, e.g. B. for breeding, these funds can be used sensibly, as long as the respective advantages and disadvantages as well as the side effects are known and are taken into account.
In the long term and for larger aquariums, osmosis systems or ion exchangers make more sense and are cheaper to reduce the carbonate hardness and the pH value.