i have an aga rr 120 gal with dual megaflow tank. when i shut off the power water keeps reverse siphoning back into my sump eventually filling it up and overflowing, i read somewhere that drilling holes in the return would stop the siphone by releasing air into the return. can anybody pls show me where to drill these hole (pls post pics bc if i drill in the wrong place is not fixable) or is there anything else i can do besides drilling holes. thx in advance



