I have an inground pool, 30,000 gallons. There are two "step jets" (returns in the steps out of the shallow end) and four other returns. I think I would get better circulation if I closed the step jets and just used the four other returns. (The builder said the returns on the steps is to help keep them clean.) However, I don't have a valve to do this. Instead of incurring the cost to re-plumb the equipment pad and add a shut-off valve for these two returns, is it okay to just screw in my winter plugs? I have some rubber plugs I usually use when closing, but I also have some that screw into the return fitting. Is there any harm in just closing them off this way? Too much pressure build-up in the line or anything? This seems to me to be the easy and cheap way to do it.