Hey NM:
I forgot to mention in another post but a mod you can do so that the sponge is not required to help eliminate air bubbles.
All it takes is some PCV pipe. But a "T" that is big enough to go on the output tube. A note of clarification, put it on the pice that slides to adjust the water height inside the chamber. I have the "T" positioned so that the top is open and then that leaves a 90 degree slot for the exit. Next buy the correct size of PCV pipe and run it as far as you want then a 90 degree fitting to point things back down and finally some more PCV to run the exit down to water level so you don't splash.
Hope it helps.