Calcium hydroxide, USP (Kalkwasser). Calcium hydroxide ("Kalkwasser"), >99.0% purity (exceeds purity of most USP-graded material). Provides calcium, increases pH. Kalkwasser application is an integral part of an effective pH-management and coral growth regimen in dedicated coral culture systems.
 
This pack contains sufficient calcium hydroxide to prepare 50 gallons of saturated solution (6.5 g per gallon).