Monitor the health of your saltwater reef aquarium with the Reef Professional Kit for Calcium, Alkalinity, & Phosphates. Water quality is the most important aspect of a healthy reef aquarium. Remove subjective results and guesswork by confidently testing with Hanna Instruments. Bridge the gap between simple chemical test kits and expensive instrumentation with this convenient, professional kit. Digital equipment for accurate results. Complete kit includes everything you need, so you can start testing today. Specifically chosen for use in saltwater reef aquariums.