Contains one API PHOSPHATE TEST KIT 150-Test Freshwater and Saltwater Aquarium Water Test Kit, including two bottles of testing solution, two colour cards and one glass test tube with cap Reads phosphate levels between 0-10 mg/Litre Helps monitor and adjust pH and prevent invisible water problems that can be harmful to fish and corals Reducing phosphate can help prevent excess and unsightly algae, which can cause fish stress and inhibit the growth of hard corals Use for weekly monitoring and when water or fish problems appear