IMHO In addition to the mentioned electrical demands and cooler water temperature I don't think it is a matter of additional benefits. I think it is a matter of are the benefits of running it 24/7 worth the extra electricity. I don't have cold water fish and want the maximun benefits of aeration. So I come down on the side of full time running. I have also read somewhere that turning it on and off, even once per day, is harder on the carbon blades, motor, etc. than just letting it run.
Bing
