Water parameters in ponds: phosphate
When looking at substances that contaminate pond water, phosphate plays as important a role as nitrate. Phosphate mainly gets into ponds as a result of fish waste but also from rotting plant matter and leaves. Phosphates can be either dissolved into the water or chemically bound, e.g. in the substrate. A layer of sediment can therefore act as a permanent source of phosphate.
Although phosphate is a building block of life for all creatures and therefore essential, an excessively high phosphate level can also lead to an algae plague. This can only be avoided through a suitable fish stock, proper feeding with high-quality brand foods and proper pond floor maintenance. However, phosphate-reducing products from specialist retailers can also help. As a general rule, regularly removing the sediment from the pond floor, frequently conducting partial water changes and adding a sufficient stock of plants can keep the phosphate level in check over the long term.
• Good phosphate level in ponds: as low as possible