I have an SM100 style clone that sits above the tank. I have a pump in the display tank deliver water up and out, and then a 2" bulkhead (1" pipe) as the return back into the tank. There are three 90 deg turns that pipe makes, and I have a 1" to 3/4" coupling at the end to slow down the return water. My problem is when I have the flow turned down so the water level in the scrubber is right, I get a siphon forming at the drain that is loud and causes millions of bubbles in the tank, which is ugly and causes outrageous creep. So I have to turn up the flow which elimates the vortex in the drain, but also causes the water level in the scrubber to be pretty high. How can I have lower flow but avoid the gurgle, the vortex, the siphon the bubbles and all that? I don't understand water flow enough to figure out what I can do. The follow up post will have some pics of the setup. Thanks all!