Dave,

I ordered 2 of the coolers from the other thread on water temps and I received them a few days ago. I had to go buy a "key" yesterday. My question is if I have these on my returns, won't this greatly reduce the effectiveness of my skimmer? The water won't be circulating around the pool, instead it will be going in the air. My skimmer doesn't work too well to begin with, so I guess I will be skimming my pool a lot more often. Do you leave yours in all the time, or remove and replace as needed? TIA.