For the 75 gallon cichlid tank and have a question. With all the rockwork in many cichlid tanks (Malowi in particular) I'm wondering how people keep wastes from collecting in caves and in between rocks where you can't vacuum. I vacuum weekly when doing water changes and can easily move the driftwood and few rocks occasionally to get at the harder spots but with a huge rockpile that's not really doable. I do plan to have good water circulation with a couple of power heads in addition to a canister and HOB filter that I guess would help but do many do the undergravel jet thing to really keep things moving? I really want to get this right before commiting to one particular design. Thanks.