I built an incubator from a 10 gallon fish tank. I have it set up with a water heater thermostat, computer fan, and a 60 watt bulb. The thing is, I dunno if it's dumb luck, but my temp in my dummy egg (blown egg filled with gel) is staying at 99F, and the digital thermometer stays at 101.3 The thermostat never shuts the light off. I know it works, because when I unplug the fan, about 2 minutes after, the thermostat shuts the light off. I plug the fan back in and within 30 seconds, the light is back on. Did I totally luck out, or am I over-looking something? I ran the incubator for 3 hrs tonight, and that's the temp that it reached, and that's where it stayed.