Maintain a healthy saltwater aquarium free from dangerous chemical levels with API’s Saltwater Master Test Kit. This easy-to-use kit quickly tests water four different ways to protect marine fish and invertebrates from dangerous water conditions, including high-range pH, ammonia, nitrite and nitrate. API’s Saltwater Master Test Kit offers accurate professional results every time. This four-in-one test kit comes with four test tubes, a waterproof holding tray for testing bottles, a test tube rack and complete instructions. Simply use the test tube to collect a water sample, add the provided solution for the specific test, shake and check your results against the color-coded chart. Each kit features more than 550 tests. Test the water in your tank once a week to make sure the levels are stable and to prevent harmful effects on your fish and aquatic environment.