To be honest, I'm having a tough time wrapping my head around that one also...

I am measuring the temps with an accurite thermometer from Walmart, the ones everyone has, IN ADDITION TO a $90 thermostat probe. It better be reading temps accurately for that price! The room temp is usually about 74 give or take. It may be cooler when my bf leaves the fan on (like I said he complains of heat, but I'm as cold blooded as my snakes. I'm always freezing).

The flex watt covers approx. half the tank (it's an 11" strip) and the tank is about, probably 10" above the ground. It rests on the shelf below my large bird cage so as not to take up any more space. Plus, that's the only available plug right now.