I read a lot about people having trouble keeping the temp regulated in their bators. Several years ago my son and I build a bator using an old ice cooler. Someone told me to put a few bottles of water in it to help keep the temp constant. I don't know if it helped because we never tried it without the water, but we didn't have much trouble with the temps. I do recall putting hot water in the bottles to get started. Anyone else ever try this? I am planning to build another bator soon, and I am wondering if I should leave room for bottles of water. The guy that told me about it actually used a rubber hot water bottle in his.