I just installed a through the wall, wide mouth skimmer (Hydro Tools 8939G) on my 26' x 52" Intex pool. I haven't cut the vinyl for the opening yet because I have quite a few leaks around the face plate assembly. Installed in this order beginning with water side: Face plate, gasket, liner, gasket, housing assembly. I've tightened every screw as tightly as I can, still several trickles. Did i do something wrong or do I need to do something differently?