Ok so I have an Intex 18x52 XTR with 1 return and 2 inlets or vice versa. I installed a wide mouth skimmer and now want to shut off the 2 inlets. I'm going to cut out the 1 1/4 size holes to make them 1 1/2 size holes (I know I know). My question is what do I need to buy to close off those 2 holes?