[mike31154]

If it's doing such a great job producing nasty skimmate, I'd be inclined to give it a bit more time before throwing in the towel. How & where does the return line enter your display? If it's low in the water, raising it (if possible) might allow the micro bubbles to disperse to the surface before they mess up your visual enjoyment of the tank. Might also try splitting the return into multiple outlets with a tee to distribute the return flow a little. Or even a small box in the display to capture the return flow. This would contain the bubbles. It would need to have openings or be partially submersed to allow the water to escape.