Maintaining good water quality is the key to successful fishkeeping. With the API Freshwater Master Test Kit you can test the most important levels in your freshwater 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 Freshwater pH High Range pH Ammonia Nitrite and Nitrate. Kit features computer-analyzed laminated color cards instruction booklet 4 test tubes a holding tray and test tube rack.