Looks great! Love the enclosure.
I would imagine that running the pipe into the water would greatly help. I don't know if you have ever used a Python, but if you are filling your tank with one and hold it above water it causes a lot of surface agitation, but if you hold it below, then there is a sort of buffer zone that allows the water to slow down and escape les aggressively through the bottom of the tube. Have you throught about a spray bar? Just attach a T joint or something similar with holes drilled in the pipes coming out of the T. You can have it above or below the water level and it should work.