After some reading last night, I went ahead and built a reactor. Simple one out of PVC, no bio balls or anything, and connected it on the return flow. The only difference is I couldn't find any plugs, but instead had to use threaded inserts and caps where a plug was required. I had read that a larger diameter was better for total diffusion and there where thoughts about a smaller one actually promoting micro bubbles, so I went with 1 1/2" diameter. I tried to go shorter, but somehow I still managed to build it about 22" tall.

It's been functioning on my tank for a little over 3 hours as I post this, and so far I'm pleased. The same volume of CO2 is being placed into the system, my ph is about the same, but I have lots of of tiny bubbles! And since I was able to direct my filter return flow into the tank so to speak instead of at the diffusor, I can now blow those bubbles clear across the tank.

During the first hour or so, the bubbles where of larger size and from what I read probably made up alot of air bubbles. But now the bubbles are smaller than any of the diffusers I have used. I used to be able to sit 15' away and see the bubbles, now I have to be up close to the tank to see them.

Plants are pearling the same or better than before the reactor, plus, everything is covered in bubbles. I'm not going to say yet that it's ALL pearling. If I loose the tiny bubbles as things settle in, I will build another reactor smaller in size, as I still want to follow the micro bubble theory. I'm also noticing some speedy growth ona couple of fast growers, like when I first set everything up.

I know I probably didn't give diffusors enough of a chance, but if this works well... I like it.

But so far so good!