Ahhhh Like everything in life there are no absolutes. ( Except maybe vodka ) anyway, as you can see for his application it would make sense to me as well to keep the aerator running. But everything has to be looked at carefully to come to the right conclusion to a persons application. I might not give the same advice to someone trying to raise trout, but then again I think I would need more information as to where the spring is going if it is not exiting the pond and how cool the spring is and how much O2 is in the water from the spring.

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1/10 - 1/4 acre pond plus 16 ft deep/ Plus 40 ft by 20 ft by 6 ft deep koi and fathead minnow pond next to it. Upstate NY