AquaLife Phosphate Remover is best used in smaller quantities with frequent changes. In an environment with an excessively high phosphate reading, it may exhaust rapidly in 6-10 days. Place the product in a high flow rate area and test your phosphate levels. Change as needed. When aquarium levels are below 0.2 ppm (mg/L), leave that portion of it in the filter. AquaLife Phosphate Remover may yellow somewhat as it picks up organics, but that is not an indicator of exhaustion of phosphate removal. Continue to test weekly for phosphate until you see it begin to rise again. You will then know that it is time to be changed. AquaLife Phosphate Remover will absorb the silicate, as well. AquaLife Phosphate Remover is inert and safe to leave in the filter. This phosphate remover will perform better than competing products and is economical to use. It is reef safe and good for freshwater or saltwater applications. The tremendous bead design has superior flow characteristics. It does not release phosphate or silicate back into the water.