Reef calculator

Rock Calculator

A starting point for how much rock to buy, based on the look you want.

gal

How this works

The old rule of 1 to 2 lb per gallon came from heavy live rock. Modern dry rock is lighter and more porous, so most scapes land between 0.5 and 1.5 lb per gallon. Live rock holds water and weighs about a quarter more.

Rock

Questions

Is more rock better?

Not anymore. Flow and swimming room matter more than rock mass. An open scape is easier to clean and gives corals room to grow.

Dry rock or live rock?

Dry rock avoids pests and needs a longer cycle. Live rock brings life with it but also hitchhikers.

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