Water displacement

[Puterguru]

Just wondering how much water ,lets say, a 75 gallon tank actually holds when filled with the 1.5 to 2 pds per gallon Live rock.

Is there a formula for this?

Sorry if this has been asked before, just something I started thinking about.

[rbaker]

It depends on the density of the rock. I'd guess you'd actually have around 50-55 gallons with that much rock in a 75...

JMO,

Ryan

[WaterKeeper]

I usually figure about 1 gallon of water for every 10.5 pounds of rock. As Ryan says it depends on the density so this is only a rough estimate.

[Randy Holmes-Farley]

It also depends on what you mean by displace. That is, on whether you are counting all of the water in the pores of the rock or not.