Hello. I just purchased a INTEX 20 X 48 pool with a skimmer filter that hooks up near the top of pool ( I have never seen this type before). There is only one hole to to the left of the filter. I think the filter is a fs 1000, which I'm guessing means 1000 gph which is not enough of this large a pool. I'm looking at buying a 2000 gph filter/saltwater combo for it, but not sure how to hook it up. We had a 12x36 pool a year ago, so that is my only experience with pools. Any help would be greatly appreciated.