[kevinj]

I have 59 gallon lightly planted tank with a Eheim 2217 canister filter, a pressurized CO2 system (with regulator and solenoid) and a CO2Arts Bazooka In-Tank Flux CO2 Nano Diffuse.

My question is where to place the diffuser. I've read conflicting answers. Currently I have it the filter outlet all the way on the left of the aquarium. The filter intake it all the way on the right of the aquarium. The diffuser is next to and slightly under the filter intake. Most of the bubbles get sucked into the intake and the rest disappear before hitting the surface.

One suggestion want to move the diffuser the left side of the tank under the filter outlet with the filter intake all the way on the right of the tank. Therefor the bubbles get "blown" across the tank.

My limnology background leads met to believe that neither placement would make a noticeable difference in such a small, closed controlled environment. To me (and I could easily be wrong) your splitting hairs and there is a minuscule difference between the two.

IYO which is "better?"

 

[adiastra]

When using a diffuser, The only thing that matters is that the CO2 is dissolved in the H2O. The best way to accomplish this is to allow the bubble maximum time in contact with the water. That being said, agitation helps the process, so letting it run through the filter is probably going to net you slightly better results as the bubble is forced to endure maximum agitation. HOWEVER if your filter outlet agitates the surface, its a moot point since gas exchange will happen at the point of surface agitation. I place my at the lowest possible point in my tank on the end where the outlet is. Thes allows the "blown across the tank" effect which gives me consistent results.