They didn't even use the return hole, that also goes over the top.But I think I know where they are, under the deck. So maybe my 10 year old granddaughter is good with tools. The pump isn[t to far from that point. personally I think through the wall would be much easier. We've been fighting green for three weeks now. Dh thinks he got all the crap off the bottom today, so I'll cross my fingers.