This is just a suggestion. You've probably already tossed around the idea.
I use a small submersible fluvol in my 3 gallon and my 5 gallon nano's, to filter and help diffuse my C02.
I simply drilled a hole in the side/bottom of the fluvol the same diameter as the hose the C02 runs threw and inserted it into the fluvol.
I've noticed the bubbles will build up in the sponge for awhile, helping diffuse the C02 before it ever gets spit out the out take on the fluvol busting it into a million little tiny bubbles further helping to diffuse the C02.
I've had my 3 G set up for 6 months give or take, no algae and the 5 G has been set up for over a month now with no signs of algae what so ever.
I really really want to get pics of them for you guys, but I cant seem to get a clear pic of them that gives them justice.
I have a crappy 2 MP cam, any suggestions on what I could do to get a clear pic?
(not trying to hijack pseud)