I'm following you John!
That is what I am concerned with when I get back and turn it on there is no odor from the bubble plume. Other than an O2 meter is there a way to check lower water. Does anyone know of a reasonable priced meter?
I would think that you could loosely correlate water temps to O2 content. What I mean is that without aeration my pond has held about a 10 degree F difference from 18 inches below the top surface to 7 feet down. I expect aeration to change that and narrow the gap. Let's say that I get my aeration system up and running 10 hours at night and find that the delta T between 18" and 7 feet becomes more like 2 degrees instead of 10. If I would shut the aeration system off for a week and I came back to check the temps and found that the pond was showing the 10 degree difference again (or close), I would assume that the thermocline had moved up the water column and the lower water had lost significant amounts of O2. I would hesitate to just turn on the aeration system without going through the typical start-up procedures.
Seems like the rule of thumb we might be looking for? - At least for an established aeration system with no toxicity issues at the bottom. A gassy smell would nullify the rule and demand the start-up procedures regardless of a small delta T.
