CaribSea ReefCal (473ml)
ReefCal™ is a 100,000 ppm ionic calcium solution. ReefCal™ will raise calcium levels by just over 5 ppm per capful (5ml) per 25 gallons of water. Use a good quality test kit to monitor dissolved calcium levels in the aquarium. ReefCal™ should be used with a buffer like BufferPlus™.