Phosphate (PO4) build up in the tank appears to be a fairly common problem in freshwater and saltwater aquariums. They are present in most tap water supplies, they are also introduced to aquarium water through fish waste, uneaten fish food, and decaying plant and invertebrate material.

Hobbyist end up with rising levels of PO4, leading to the appearance of algae that start to cover the tank panes, the driftwoods, the substrate and just about anything else in the tank.

The maximum value of PO4 in aquarium is:

     • for seawater aquarium 0,01 mg/lt

     • for fresh water aquarium is 0,5 mg/lt. In deeply planted aquarium the maximum level can achieve up to 1 mg/lt

The periodical analytical valuation of phosphate in the aquarium water should be considered by the serious aquarium enthusiast.