This weekend I will start working on my 75 gallon tank. I had just started to make decisions about what type of flow I was going to have, powerheads vs closed loop when the person whose supposed to help me drill the holes is trying to talk me out of a closed loop . This is my very first drilled tank and I want it to be as clean inside the tank as possible. I dont want wires or powerheads all over the place. My first of many questions is, on a closed loop how do you block the holes so that an octopus doesnt get in them? I was thinking screening but that will eventually be blocked with crud from the tank so I dont know that it will be a viable option in the long run. If I had 1 inch holes drilled in the tank for the closed loop he said I would need a very strong pump... something like a mag 24. How much flow is to much flow for an octopus? I feel like a virgin octopus keeper all over again .