I started off with a new Intex 15' x 48" circle pool last summer. It came with the smallest pump, 637R, which pumped around 1,000 gph (I think). I installed a much larger pump - Intex 633T, which pumps 2,500 gph.
I'm going to purchase an Intex skimmer which attaches to 1 of the 2 strainers...