Originally Posted by Animal-Chin
Won't the liverock die in a canister filter? No light gets in at all. Whats the benefit or having the rock in there?
The rock is just a porous substrate for bacteria to grow on. The more effective surface area it has, the more bacteria it can host. Light has nothing to do with it as the bacteria doesn't need it to grow. The live rock buried in your reef never sees light, but it does it's job fine. The more live rock in the system, the better off you are IMO
. The classic setup is just tons of rock, a protien skimmer and lots of flow.