ted:

The other issue with leaving it off, measuring the O2, then turning it back on if the O2 is low, is mixing the hydrogen sulfide that builds up in the anoxic water. You shouldn't have an issue turning it back on if you catch it when the O2 at the deepest level of the pond is middle 4's to 5's mg/l, but if it's down below that and there are fish in there, you'd be safe to do the 15 min day 1, 30 min day 2, 1 hr day 3, etc. startup procedure to avoid mixing too much hydrogen sulfide in the water too quickly.

What are you going to use to measure the O2 levels?

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