ROWAphos is a completely new filter material for eliminating phosphate. Due to its unique chemistry, it has the ability to bind large quantities of phosphate by adsorption to its surface without negatively influencing the water in the aquarium in any way. Why is a phosphate removal system necessary? Phosphate (PO4) in the aquarium is caused by the decomposition of organic substances. Especially in the confined habitat of an aquarium, several of these decomposition processes are caused from food surplus, dead plant and animal matter, and excretions (animal waste, etc.) It is very important to maintain PO4 concentrations at very low levels which are in harmony with the aquarium\'s life and habitat. Natural waters that have not been negatively affected by human use typically show very low PO4 concentrations. However, it is nearly impossible to maintain this ideal condition in an aquarium without an artificial phosphate removal system.An increase in PO4 concentration leads to unwanted growths of nuisance algae, and to the inhibition of lime synthesis in certain specialized marine organisms in saltwater, such as calcareous algae and stone hard corals. What are ideal phosphate levels for freshwater and saltwater aquariums? To correct phosphate-induced problems, it is recommended to always keep the concentration of phosphate less than or equal to 0.15 - 0.3 ppm in freshwater aquarium systems (expressed as phosphorus P.)In saltwater aquarium systems, phosphate levels should always be kept below 0.015 - 0.03ppm (expressed as phosphorus P.) How is ROWAphos used to maintain ideal phosphate levels? The phosphate targets mentioned above can be easily reached with ROWAphos, which effectively binds PO4 without negatively influencing the water in your tank. With ROWAphos, release of potentially toxic substances like aluminum will NOT occur. When exhausted, the product does NOT release phosphate back into the water. ROWAphos should be used regularly, especially in aquaria with very sensitive fish (discus, for example) and in reef aquariums with complex living systems. ROWAphos can either be used in a canister filter as a separate slow phosphate filter, or, alternately, it can function at the end of the main filter system as the final stage, after the biological and mechanical filters. The material can either be used in the filter net supplied with the pack, or sandwiched between two layers of fine filter wool (on the incoming and outgoing flow.) The amount of ROWAphos required is determined by both the level of phosphate in the water and the level of phosphate in the rocks, gravel and other substrates within the aquarium. On new or established aquariums where the phosphate levels are high, first measure the level in the water and assume that 2-4 times that amount may be bound up in the substrate; then adjust the ROWAphos amount accordingly.