Originally Posted by joseramentol
So how about if I just run a canister filter instead of hobf
I am not an expert on canister filters but I know they make canisters that have both biological and mechanical filtration. So I don't see why not.
Yes you might need more than the 750, technically you would need 1500 per the 50x rule. But you also have to judge it by the corals that you plan on keeping as well as what 1500gph does in your tank. Two 750's from koralia create a wide spread out flow and you might be ok but your substrate depending on what you have might get blown around like a hurricane. Just from my experience. I hope someone with a 30g will chime in and give you better advise.