Red Sea’s Phosphate Pro Test Kit is an advanced colorimetric test with comparator, measuring the level of phosphate in your reef aquarium to an exceptionally high accuracy of 0.02ppm PO₄. Phosphate Pro Test Kit, when used in conjunction with the Nitrate Pro Test Kit, enables accurate dosing of Red Sea’s NO₃:PO₄– X (Biological Nitrate and Phosphate reducer) which is part of the complete Red Sea Reef Care Program.