Hey folks What return pumps do you all use for a tank this size? I'm not referring to flow rates/etc., I know about that. I'm wondering what brands you have had success with and would recommend. I am not opposed to an external pump, as long as the water inlet fitting can go through a 1/2" hole(the only glass bit I have ). In a tank this size, I'm sure there are a few submersibles that do the trick though...I just want to make sure it is quality and doesn't produce any microbubbles. I assume there are no microbubbles when using the impeller-less models...is that correct? Is it the cavitation of the impeller that causes them? Reason I ask is I am through with powerheads, all they do is make micro-bubbles and take up the already limited tank space. I am upgrading to a sumpfugium, and I am using a water return manifold as my sole source of circulation. I just want to make sure that I purchase the right pump here, as I will be beside myself if I buy and new pump and the microbubble situation continues....it is driving my batty. Thanks for any input you may have Peace