Thanks for your input!
Question: Is using Excel different than if i just turned the bottle up? Arent they basically doing the same thing, adding co2?
As far as flow, my plants are swaying. The 2217 puts out some decent flow, but the spraybar lies only a few inches below the water line. I have the Koralia on the opposite end...maybe i'll put it under the spray bar (which is on the side glass)