Hi Brian,
Thank You. Now that you mentioned it--that does sound familiar. I just couldn't recall the specifics (still can't actually). But common sense does point toward diminishing returns, both for the plants and for out-gassing.
My only real issue is measuring the C02 level. I have a DC, but the suction cup is shot, so I either have to come up with a new one or jury-rig the thing. I can move one of my pH controllers over to this setup, but then the probes need calibration and, and, and,....sheesh. Yeah, I'm lazy, but I've also been busy with other stuff.....
Still need to do all the math and get my peristaltic pumps setup.......
I'll see what I can come up with. I'd really like to grow some of this stuff.....