Maintaining good water quality is the key to successful fishkeeping. With the API Saltwater Master Test Kit you can test the most important conditions in your marine aquarium. Plus this kit includes step-by-step instructions on how to perform each test how to interpret the results and how to correct unsafe water conditions. Includes High Range pH Ammonia Nitrite and Nitrate. Kit features computer-analyzed laminated color cards instruction booklet 4 test tubes a waterproof holding tray and test tube rack.