Reef calculator

Salt Mix Calculator

Mixing new saltwater or raising a batch that came in low. Enter the water and the salinity you want.

gal

How this works

Reef salt mixes need a little over 1 g per litre for each ppt, because the dry mix carries some bound water. Mixing to 35 ppt takes about 135 to 145 g per gallon, roughly half a cup.

Salt Mix

Questions

What salinity should a reef run at?

35 ppt, which is about 1.026 specific gravity. Fish-only systems can sit a little lower.

Why weigh instead of using cups?

Salt settles and clumps, so a cup can vary by 20 percent. A kitchen scale makes every batch the same.

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