Alrighty so it is a 2" line. The adapters that I ordered that amazon said would be delivered today didn't come so I ended up going to Lowe's and was able to make an adapter. I was afraid the two 1.25" inch feed lines wouldn't be enough for the pump, but it sounds just fine and WOW, does this cause a nice whirlpool. I didn't cut the hole for the return head yet as I just as the bigger return over the top and tied in place for now. I'll cut a hole in the liner tomorrow when I have day light to light things up for me.