High phosphate levels are a common and recurring issue in saltwater and freshwater aquariums. If you have a problem with algae or excess cyanobacteria turning your water green, it is likely due to phosphates. Controlling your phosphate levels is easy when using Seachem's PhosGuard in your filter, which quickly and safely removes phosphates from your aquarium.
Use 250 mL (~1 cup) for every 300 L (75 gallons). Leave product in place for 4 days, then test phosphate or silicate concentrations. If the concentration of the component you are trying to decrease has not dropped to around 0.02 mg/L, then replace the PhosGuard, otherwise leave in place until levels begin to climb again. As long as concentrations remain under control, the product is not exhausted.
Each 500 mL of PhosGuard treats over 600 L (150 gallons) (i.e. will remove up to 30 mg/L phosphate in 600 L (100 gallons) of water, depending on the initial phosphate/silicate concentrations and the current biological load. Over-treating is not recommended.
PhosGuard is not an exchange resin, it does not release anything into the water. It does not leach phosphate or silicate back into the water and may be removed, dried, and returned to service until exhausted. Continuous use of small quantities is better than intermittent use of larger quantities.