Sorry for the late response. Been a busy weekend with the storms. It's definitely finicky. I haven't done it yet but I would change out that ball valve that comes with it to a gate valve. It'll give you a finer adjustment. Until then it's VERY small adjustments to that valve. And I mean very. 1mm at a time then give it about 5-10min to equalize. I actually have to use 2 hands to turn it that small of an amount or I over do it. Just keep doing that until the flushing sound is gone. Also I'd turn your sump pump down as low as possible. Don't need to flow too fastI have this tank/stand/sump. I changed out the return to the Varios2 and the sump to the 110-INT. I finally added the water today and I'm struggling to dial this thing in to cut down the noise. Any suggestions? Also, the water level in the display tank is about 1.75" from the top which looks ridiculous. Your pics look less than that.