Okay, I drained the sump manually to a desired level and then shut off the pump. Water movement seemed to have stopped entirely after the overflows lowered to the valve levels.
I turned it back on and it drained to maybe 1/2 of an inch higher than where I had manually lowered it. So it's basically just above the eggcrate now which is ideal for me. It's now running correctly I hope.
There are a couple of things I think it could have been that I want to run by you guys:
1) The return pump seemed out of place in the sump, with the intake up against the back glass as opposed to tucked in towards the front of the sump without nothing impeding the pumps intake. It may have been moved from vibrations/me working and not realizing I moved it. It's back in place now.
2) I did a small water change this morning before work. This was my first water change of the 500 gallon and I am wondering if this could have caused it without me realizing it. If so, are there any water change tips you guys have for me? Maybe I added too much water back in than was originally there?
Seems to be fixed now, but I'd like to make sure I keep this system running as smoothly and as such try not to let it happen again. Thanks guys.
Michael