We tried something similar in our bare floor tank. We had PVC pipes laid out on the floor in an E pattern. The PVC pipes had holes drilled in them. They didn't work as we had hoped. We then ran two vertical uptake pipes just off the floor. They were placed where the debris tends to eddy. These poop sucker pipes work fantastic! Others have just lowered their uptakes to just off the floor and also really liked the results. There literally has been nothing to vacuum in years, as the poop sucker pipes remove all debris.