Here's my take on it. Its a little simpler and probably cheaper (im lazy and cheap lol) Just a hole in a simple lid that is nearly the same size as pvc (doesnt need to be water tight). Then a threaded barb in the side. There not ganna be a ton of flow through these. I just think makeing a water tight top with nylon screws is ganna be a nightmare
This is basicly the same exact design Mike used on the Diy Kalk reactors. Simple and works
Where can we get large cell foam? I have a few chunks from my old aquaclear 75, but if we are making lots we'd need need a source.
I wasn't as bored as josh to draw it up in Sketchup.
but i think the blue from the water contrasts nicely with the brown of the GFO tumbleing on a bed of foam