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. DIRECTIONS:BEGINNER: Use 1 capful (5 mL) per 80 L (20 gallons*) twice a week. Check calcium every 2 weeks and adjust amount or frequency accordingly. ADVANCED: Check calcium level, then follow dosing regimen above until calcium is adjusted to 380–420 mg/L. Each capful will raise calcium by about 10 mg/L. Size or frequency of amount added can be adjusted, but do not exceed 25 mg/L per day. Thereafter, use as required to maintain calcium. EXPERT: After determining the calcium consumption rate, set up a continuous drip system. Use the following formula to determine how much to add to your top-off water: m=0.025vc (m=mL of product to add to top off water, v=volume of tank in gallons*, c=amount to raise calcium in mg/L). For example, if you want to raise calcium by 20 mg/L in a 50 gallon* tank, then you would add 0.025x50x20=25 mL into the top-off water. HINTS: If used with Reef Calcium™, it is not necessary to exceed 380 mg/L total calcium. Calcium over 400 mg/L is not recommended. Use Reef Status™: Calcium to measure calcium. 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.