Hanna Instruments Marine Reagents are precision-formulated chemical solutions designed for use with Hanna’s marine colorimeters and checkers. They provide accurate and consistent testing for key saltwater parameters such as calcium, alkalinity, nitrate, nitrite, and pH. Each reagent set delivers reliable results essential for maintaining optimal water chemistry in reef and marine aquariums. Ideal for hobbyists and professionals, these reagents ensure precision, consistency, and ease of use in regular water testing routines.