Seachem Reef Complete Liquid ionic calcium source 160,000 mg/L (most concentrated on the market) vs. 100,000 mg/L 100% soluble. Be wary of products that are milky white or need to be shaken Seachem Reef Complete is a concentrated (160,000 mg/L) optimized blend of ionic calcium designed to restore and maintain calcium to levels found in natural seawater without affecting pH. Calcium and carbonates are essential to all coral growth. If either becomes deficient, coral growth will cease, followed by a rapid decline in coral health. To prevent this you must provide calcium (Reef Complete®) and carbonates (Reef Builder™ or Reef Carbonate™). Reef Complete® also includes magnesium and strontium in amounts proportionate to typical utilization ratios (100:5:0.1, Ca:Mg:Sr). This allows one to maintain these two important elements while maintaining calcium. Why It's Different Reef Complete® is a blended product. It is not simply calcium chloride. Commercially available calcium chloride contains ammonia. Unlike other ionic calcium supplements, Reef Complete® is blended to a higher pH in order to force the ammonia to gas off into the atmosphere. In addition, Reef Complete® is more concentrated than any other liquid product on the market. Reef Complete® contains 160,000 ppm calcium. Our nearest competitor’s product is only 110,000 ppm calcium. Directions Use 1 capful (5 mL) per 80 L twice a week. Check calcium every 2 weeks and adjust amount or frequency accordingly. DO NOT OVERDOSE: Excess calcium may enhance the loss of carbonate alkalinity. Do not directly mix with any carbonate supplement. Best if calcium & carbonate additives are added on alternate days or at least 30 minutes apart.