Reef calculator

Calcium Dosing Calculator

Raise calcium to your target with calcium chloride or your own product.

gal

How this works

Each ppm of calcium in a gallon is 3.785 mg of Ca. Calcium chloride dihydrate is 27 percent calcium, so that is 0.0139 g per gallon per ppm. We keep a day under 20 ppm.

Calcium Dosing

Questions

What calcium level should I run?

400 to 450 ppm for most reefs. Keep alkalinity and magnesium in range too, or calcium is hard to hold.

My calcium will not go up. Why?

Low magnesium is the usual cause. Test and correct magnesium first.

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