The Red Sea Pro Potassium Test Kit contains 40 TestsElement: Potassium (K)Accuracy: 12ppmTest Type: TitrationTest Range: 150-450 ppmNumber of Tests: 40All Red Sea Pro Test Kits come in a durable plastic housing and use optically clear, analytical lab grade glass test vials.Used for the testing of Potassium in the aquarium.Can also be used as part of the Stage 2 - Algae Nutrient Control in the Red Sea Reef Care Program.The Algae Nutrient Control Stage provides a complete solution for testing and controlling nuisance algae and promote coral coloration. This products is part of the new Red Sea unique Reef Care Program (RCP).The Red Sea reef care program is the result of over 5 years research from Red Sea scientists resulting in unparralleled understanding of the requirements of coral aquariums. The Red Sea Reef Care Program provides a holistic solution to maintaining a flourishing coral reef aquarium.It even allows beginners to achieve stunning sps aquariums safely.