Proper pH control is imperative when caring for fish in a freshwater aquarium. Water that is either too alkaline or too acidic can have harmful effects on fish and plant life, so it's important to maintain consistent levels to keep your fish healthy and your aquarium thriving. This API pH Test Kit is a simple and accurate way to make sure your water levels are normal and don't need adjusting. It tests pH levels from 6.0 to 7.6 and includes approximately 250 tests per kit. The pH liquid tester is both easy to use and easy to read; all it takes is a few minutes each week to make sure your water levels are safe and properly balanced. Simply fill the provided test tube with 5 milliliters of water and add three drops of the pH solution. Mix gently and compare the colour to the solution to the test's colour card to read your results.