Fing out the weight of one gallon of sea water, it will be a little over 8 pounds. then divide the weight of rock be that and it will give you an approximate displacement.
I have four 48" vho lights with ballast for sale for 200.00. they are about three months old. if interested you can post here or email me at jpweber2@cox.net
i just bought a calcium reactor and want to make sure that i am setting it up right before i start using it. do i need a check valve between the co2 bottle and the reactor and what kind of fluid do i need to put in the bubble counter?