I've just made a still air incubator but can't get the temperature stable. I'm using a hot water thermostat like all the home mades suggested but the best I can get it too stay is a high at 103 or low of 91!!! Isn't 91 in the too cold range? How do I get the temp to be more even? Would a fan do it? The Radio Shack in our town is lame and doesn't carry computer fans, infact they looked like they only sell cell phones now I tried checking office depot and nothing... and Walmart doesn't have any either. I'm bust as far as stores go. I try to avoid ordering things over the internet if I can.