Actually, the only thing new is the powerhead After hearing all this reactor talk and seeing the nagging BBA in my tank even after massive amounts of CO2, I had to put one together. It's made from a Rio 600 and a gravel vac I had laying around. After making the connections, I fired it up. I've yet to add the venturi feature. I just want to watch the bubbles for awhile

About the venturi: Do I need one? The tube is a good 12" long, and a few small bubbles escape the bottom and rise up. However, I have a Hagen 802 powerhead with the quickfilter attachment hanging right next to the reactor. Since I turned turned on the reactor, the 802 is spraying an ultra fine mist of CO2 all over the tank. It never sprayed bubbles before.

Anyhow, if I add a venturi, I think there are a couple of ways I could do it, and possibly do it more effectively than returning it into the reactor. One way would be to run a tube into the outlet on the 802. There is an inlet on the outlet ( ) which is usually used to inject air. Another way would be to run a tube into the quickfilter (pre-impeller smashing). Another way still would be to run a line into the intake of my Eheim 2028. I figure that way would give the CO2 the most dwell time. Then of course I could just run a tube into the spraybar.

Suggestions?

Tubes are cheap(viewtainer.com) so you can try both, the venturi will help with growth.

The more folks try to improve the CO2, the better.
You can see results rapidly and it has a large impact on both plant and algae growth.

Regards,
Tom Barr