Sorry for the late response to you questions guys. My schedule has been hectic.

My filter is a Posi-FloII Sta-Rite Mod# PTM70. Cartridge filter type.

I bought the filter at a local pool store, i think the filter brand is dolphin.

There is a valve at the bottom of my filter housing that I can open and it let out water. I have used this when the pool gets to high from the rain. But there is a hole at the bottom of the skimmer I have never used. I can't figure out what it is for.

Thank you all again for your time.