This was in the bottom of my skimmer basket. The pool builder is gone and I'm trying to finish the pool and do the startup myself. As I recall from my last pool, I think this gets installed inside of the skimmer down at the bottom and adjusted partially open. Is this right from my recall or am I totally lost? Seems I remember seeing this at the bottom. If so, what percentage should it be open? Which side does it go on...there are two holes in the skimmer basket I think...its filled with too much junk currently to tell completely though.