Reef calculator

Magnesium Dosing Calculator

Bring magnesium up so calcium and alkalinity stay stable.

gal

How this works

Each ppm of magnesium in a gallon is 3.785 mg of Mg. Magnesium chloride hexahydrate is 12 percent magnesium (0.0317 g per gallon per ppm). The 5:3 chloride and sulfate blend keeps sulfate from building up. We cap a day at 100 ppm.

Magnesium Dosing

Questions

Why mix chloride and sulfate?

Natural seawater has both. Dosing only one shifts the balance over months.

Is Epsom salt safe?

Plain Epsom salt with no scent or additives is magnesium sulfate. On its own it is fine for small corrections.

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