Keeping a saltwater tank? Monitoring pH is crucial for your fish and corals. This NT Labs kit uses precise liquid drop tests (not less accurate strips) to measure pH in marine aquariums. You get up to 40 tests in the box. It's super easy: add 5ml of tank water to the tube, add 5 drops of reagent, shake, and compare the color to the chart. Ideal marine pH is around 8.3. The kit also includes advice on what to do if your pH is too high or low, often related to alkalinity (KH). A reliable, essential tool for any marine aquarist, beginner or expert, to keep their underwater world healthy.