Join Date: Feb 2004
Location: Calgary, Alberta, Canada
I red most of that thread, skipped some bantering and such. But I think that while even though the original experiment was too uncontrolled, I agree with the idea that the bubble may not be co2. I hadn't considered this and was always under the impression that co2 becomes harder to dissolve. It makes perfect sense that it would get harder, but if the saturation point is >1000ppm I can't see the difference between 3ppm and 30 ppm to be that drastic. If we were nearing the saturation point than sure, but we aren't touching it.
You've gotten me thinking that my reactor setup was just fine, if I can prove that the gas in the reactor isn't co2. I think I'll try two little experiments.
First, start the reactor up on my tank in the morning when it's ph is highest. I get good circulation and air mixing so it should be a good reference for 2-3ppm. Fill co2 reactor with, say 30 bubbles of co2. Start reactor and time when the bubble dissolves. Then I'll wait till my ph in my tank has dropped 1.0 with a second diffusion method, and repeat the experiement with the same number of bubbles, reactor, etc. If it takes longer I can assume (for my purposes) that the diffusion was more difficult.
I can also take two water samples, one of 3ppm co2 water, and one of 30 (or so) ppm tank water and submerge a test tube in each. Invert the tubs and let one bubble of co2 into each tube. I would use the same reg setup, needle valve, etc. for each bubble hoping for consistency. Then I would cap the vials under water, taking a set amount of time to cap the vial and begin to shake it. Time how long the bubble takes to dissolve in each.