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 test tubes 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.