How do you circulate your CO2 inside your plant tank?

I am injectiong diy co2 via a powerhead in a tank that is four feet long. The powerhead is located in the lower back right corner of the tank. Is this the optimum placement for optimum co2 diffusion? Is a powerhead a good way to introduce the co2 into the tank? Lastly, if I were to try and put the output into the intake of my canister filter will the bubbles make it all the way through the filter media? I guess my concern is if the co2 is being properly circulated through the entire tank.
 
Most folks avoid injecting CO2 into the intake of a cannister. Apparently you can airlock your filter this way (and ruin it). Again it depends on the type of cannister and some people may do this, but from what I have read it is not recommended.

I have had good success with an external reactor. See Rex Grigg's site for an example. If you are using the powerhead, I guess how well it works would depend on how much circulation your filter provides, as well as plant mass. If your plants are doing well in all areas of the tank I would just leave your setup as is.
 
I am injectiong diy co2 via a powerhead in a tank that is four feet long. The powerhead is located in the lower back right corner of the tank. Is this the optimum placement for optimum co2 diffusion? Is a powerhead a good way to introduce the co2 into the tank? Lastly, if I were to try and put the output into the intake of my canister filter will the bubbles make it all the way through the filter media? I guess my concern is if the co2 is being properly circulated through the entire tank.
Trevor:

I have had no problem injecting "pure" CO2 into my cannister intake. Homebrew will contain some amount of air and this may take awhile to dissolve out of the cannister filter depending on the flow rate through your system. My system has about 10 feet of piping to get from water to pump. Bubbles do make it to the pump, but only if my CO2 solenoid is open. I also have a slow bleed in parallel and slow bleed bubbles (2 bubbles/sec) don't even make it to the pump. After the pump there is about 5 feet of pipe before the cannister. No CO2 bubbles ever make it to the cannister. My usual rule of thumb is if you want to do it, try it out and monitor results carefully. If it works out, great. If not, adjust and try again, or try something else.

Some things to be aware of:

* Where you place your CO2 tube can create intake flow problems. My CO2 is injected at the very top of the intake tube as it goes over the side of the tank. If you have any air leakage in your CO2 system, you can break the "siphon" at that point and stop the water flow. You can avoid this by feeding CO2 bubbles into the bottom of the intake and letting them bubble into the tube for example.

* Water can work it's way back through the CO2 tubing and create it's own siphon back into your CO2 generator. A check valve may not be able to prevent this in all cases. Probably won't be a problem as long as you keep positive pressure in your CO2 generator. If you forget or go on vacation, you might have tank water filling your generator...or worse.
 
I have several plants in my 10 gallon with 3 mollys and platy and a guppy. I have a biowheel filter for a 20 gallon and a underground filter. So far my plants are really growing so maybe Im doing it right about the co2?
 
Memphisgirl, the caveat to running a biowheel on a planted aquarium is that surface agitation from the biowheel will off-gas dissolved CO2 very quickly. Since you only have a "few plants" it may be they're still getting enough carbon to do the job. So I say if your plants are growing and you have little or no algae then keep doing what you're doing and don't change a thing. Nothing will invite algae more assuredly than changing tactics.
 
AquariaCentral.com