Heys guys so im all set to get the co2 working for my plants. I was think and trying different ways to day to get the smallest bubbles then it hit me. What i think im gonn a do is drill a small hole into the water intake tube on the penguin 330. From what i have read the impeller will chop up the bubbles and send t he co2 back to the tank via the waterfall.
Two questions...doesthis seem like a good diffusion method and 2. i was reading another post and some one was saying remove the bio wheel as this will remove the co2? Is this correct. If so i may have to rethink my setup of diffusion. Some people where saying remove the bio wheel all together but i dont want ot get rid of something that is ecologically good for the fish.

I'm not a fan of the Bio-Wheels myself. But that's just me.

If you build your reactors properly (sealed with silicone) you will build up enough pressure to be able to use a glass nano diffuser. I highly recommend these. You'll get the micro bubbles that you're looking for. Place the diffuser at the bottom of the tank right next to the filter intake and under the outflow. If positioned correctly, some bubbles will be taken up by the intake and the others will be disbursed by the outflow. Perfect scenario for diffusion with an HOB filter.

James, i understand the reasoning behind the bio wheel... but why are you not a fan? Also if i remove it do i run the risk of harming the fish?

No risk involved in removing it.

They don't really work half the time. For the ones I have tried, they would stop working (spinning) after a while. You couldn't clean them and even replacing it all together produced the same results. Just wasn't worth it IMO.