I suppose the question is why wouldn't he run it it the winter? Do ponds freeze over in Oklahoma? That is our issue here in the frozen north and aeration in the winter is important to help prevent winter kill fish die off. Aquatic plants produce dissolved oxygen in the warmer months, but decomposition uses up oxygen in the winter. Summer and winter kill is pretty common in shallow man made ponds if there isn't enough dissolved oxygen. When we had trout in our small natural lake we did aerate it in the winter with a visible pump that kept a section open. The people that bought it are running two bubblers out in the deep water middle and I see that as a hazard for making thin ice. If your buddy's pond has an inlet and outlet with flowing water, then he probably wouldn't need to aerate it. Spring water is not a good source of dissolved oxygen. His catfish won't need near the oxygen content that the pan fish will.
