Check the listing for details. API Reef Master Test Kit Calcium KH Phosphate Nitrate Fast Easy Accurate Results. Condition: New. Listed at 35.99 USD. API Reef Master Test Kit The API REEF MASTER TEST KIT test 4 key parameters – calcium, carbonate hardness (KH), phosphate, and nitrate – to keep reef inhabitants healthy. 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, reusable 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.API 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!Contains 7 test solutions, easy-to-ready instructions, 4 glass test tubes and color chart.