API Saltwater Test Kit The API SALTWATER MASTER TEST KIT measures the 4 most important saltwater parameters – pH, ammonia, nitrite, and nitrate – to enable easy testing of your tank’s natural cycle, and to aid in maintaining a thriving saltwater aquarium. Testing is fast, easy, and accurate, yielding precise results, and comes with 4 glass test tubes with snap-tight caps and a convenient holding tub for easy storage. This kit also includes a complete, step-by-step instructional booklet with a color chart that provides information on how to correct unsafe water conditions. Each SALTWATER MASTER TEST KIT will conduct 550+ tests, so you can get the most out of your kit for years of fast, accurate water testing. We recommend that you take a few minutes each week to monitor your aquarium conditions and create a better underwater world for your fish. Testing your aquarium water has never been so easy or accurate! Sizes Contains 550 tests and includes 6 test solutions, easy-to-ready instructions, 4 glass test tubes and color chart