I was wondering if there is a ratio between live sand to live rock. for example, I have 40lbs of live sand do I need 20 lbs of live rock? I heard that you have to have an even ratio per gallon for your tank. is this correct? any advice helps!
IMO, I don't think it's necessary to have that ratio depending different situations/variables. If you have a very light bioload, then you may be able to get away with a half ratio. For a heavy bioload, then I would do 1-2lbs of live rock per gallon. Sand and live rock acts as your filtration. Some hobbyists put some of their rock in the sump.