API Reef Master Marine Test Kit The API Reef Master Test Kit 4 In 1 measures the most important aquarium levels quickly and accurately. The Reef Master Test Kit tests 4 key parameters to keep reef inhabitants healthy. The kit is highly accurate and economical, and includes 7 bottles of liquid test reagent, 2 computer-calibrated, laminated color cards, 4 glass test tubes with snap-tight caps, holding tray, as well as complete, step-by-step instruction booklet, including information on how to correct unsafe water conditions. Tests Calcium, Carbonate Hardness (KH), Phosphate, and Nitrate. Fast, easy, and accurate for precise test results. Compact to store at home. No of Tests: Calcium (70 tests), Carbonate Hardness (no. of tests varies by water hardness), Phosphate (150 tests), Nitrate (110 tests)