Red Sea Phosphate Pro Comparator Test Kit. Element : P-PO4 Accuracy : 0.014 ppm Range : 0.014 - 1.6 ppm Test Type : Comparator No of Test : 100 All Pro Test Kits come in a durable plastic housing and use optically clear, analytical lab grade glass test vials. Used for testing of Phosphate in the aquarium. Can also be used as part of the Stage 2 - Algae Nutrient Control in the Red Sea Reef Care Program.