Beginner: Use 5 mL for every 70 L (18 US gallons) twice a week. Check calcium once a week and adjust amount or frequency accordingly.
Advanced: Check calcium level, then follow addition regimen above until calcium is adjusted to 380-400 mg/L. Each 5 mL/70 L (18 US gallons) will raise calcium by about 10 mg/L. Quantity or frequency can be adjusted, but do not exceed 15 mL/70 L (18 US gallons) per day. Thereafter, use as required to maintain calcium.