I did the same with filter intakes when I used a filter, I changed over to a sump, all I have in my tank is a wavemaker and 2 powerheads. I have a picture for example from my Cherry shrimp tank, but if your talking about the tube type intakes it can be done by cutting the pantyhose to shape, strech it and rubberband it. I have 3 freshwater tanks and 1 brackish that I keep mollys and puffers in, I have to cover the intakes on both of the intakes so the babies don't get sucked in.