The incubator has four little holes in the bottom and the place you put water is in the middle, under the egg turner. It is pretty difficult to get water in there without moving the turner and the whole thing cools down for a couple of hours after adding water. We haven't added eggs yet as we are figuring out the incubator. At someone's advice, we added a computer fan. Can we plug the holes in the bottom so that we can just add the water around the outside of the bottom? Or are these holes needed for air circulation?