Warped1, this stuff confused me too at first, but with time and a lot of reading it can be digested.
, once you get your tank, regulator, solenoid and bubble counter straightened out, the toughest part (for me at least) was getting 100% diffusion. This week I'm going to plug a DIY reactor (pvc
w/ bioballs) into the downflow of my cannister filter. The rising action of the bubble fights the falling action of the water and aids diffusion. If any bubbles actually make it into the cannister (fluval 304), they get choped up to the impellor and (I hope) completley dissolved into the water column by the time the flow hits the output nozzle.
A bigger tank w/ more surface agitation means more bubbles. Every reactor has a "max diffusion capacity": the best reactor in the world isn't going to be able to diffuse 100 bps, wheras even a somewhat crappily built reactor should be able to diffuse 1 bps or less.