I was diffusing my CO2 by placing the line into the intake of my old power filter, but I have gotten rid of the power filter and am awaiting my new Eheim canister filter. I am now looking for a new (and hopefully low cost) way of diffusing my CO2. I've looked on the net and haven't found too many ways to diffuse the CO2 using a canister filter. I am then looking at some other options. I have looked at some different DIY plans(http://www.plantedtank.net/co2reactor.html) and am thinking of trying it. I was also looking at the Plant Guild's Power reactor on Aqua Botanic. Any advice on what I should try? Thanks to all!