Water level, draining issues

[4tangs]

Hello!

Well first off thank you for such a helpful website and design info as well. So I have a 220 gallon in wall reef which I am building two SM100 clones for. The first one I hooked up with a quiet one 3000 pump and the drain doesnt seem to keep up. It fills up about half way up the window before the drain levels out. I even switched the pump out to a quiet one 2200 for less flow with similar results. Is there something I am doing wrong? I had everything made to the specs provided on this website and have the biggest bulkhead that would fit inside the unit. The drain when testing was not even hooked to a drain line so I know there was no pressure or anything building up to restrict the flow..... Any advice? The water level should be much lower, correct?

https://lh4.googleusercontent.com/-UoOqehaevJM/TvqtZIJNHBI/AAAAAAAAAbI/PwP6ggG2N5o/s512/2011-12-27_22-47-07_262.jpg

[SantaMonica]

Correct.

[Ace25]

Reminds me of what happens on a Durso overflow pipe if you don't put the air hole on the top. If the drain line is submerged in the sump it may cause issues like you describe. Well, I thought I had a solution but then I read this is happening when testing.. hmmm, that is very odd and not sure what the heck would cause that issue other than bulkhead being too small, but you wouldn't think that would be the case.

One thing I can think of to test, try gluing a small piece of air tubing to the side of the bulkhead (inside). Maybe the circle of the bulkhead is causing the issue and having something small like a piece of air tubing would allow air in the drain as well as make the water spiral out the drain instead of all going down evenly.