I run my DIY CO2
through my filter. I have been doing it this way for over a year with no impeller problems. I tried every DIY diffuser idea I could find. For deeper tanks you need something to pull the CO2
down into the tank. You can buy a cheap small power head or internal filter like this http://www.amazon.com/Aquarium-Inter...s+for+aquarium
You can find instructions on youtube on how to set it up. I did that but my powerhead was really big and I did not like the way it looked in the tank. It did produce a fine mist of CO2
though. The filter method was just easier and it works. Make sure you run the tubing so that it has to go through the impeller. This chops the bubble up and makes it absorb into the water easier. My plants grow fast this way.
I have seen some creative uses for the Fluval mini CO2
setups. One guy made a series of glass viles layed out like a pan flute and used the Fluval setup to fill it once a day. It then passively dissolved in the tank. If I can find the post again I will post a link to it. You can buy a regulator for cheap that works with paintball tanks on most sites. I am thinking of doing that. Solenoids are expensive though. That is why I have stuck with DIY