DIY Calcium Chloride (Randy Recipe 1) Calcium Dosing Calculator

DIY Calcium Chloride (Randy Recipe 1) raises calcium by 0.3698 ppm per mL per 100 L of tank water (manufacturer data: source). Enter your tank volume, current and target calcium below for an exact dose, split automatically if it exceeds the safe daily limit.

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Worked example

A 75 gallon tank (284 L) raising calcium by 20 ppm needs (20 / 0.3698) x (284 / 100) = 153.6 mL of DIY Calcium Chloride (Randy Recipe 1).

Safe dosing rules

• Never raise calcium more than 50 ppm per day.
• Test again before each additional day of a split correction.
• Dose into high flow, away from coral tissue and intakes.