Thats the thing, Im not using a thermostat on uth because it never got hot enough in the first place. If you push the substrate aside you get 83 84 ive seen it as high as 86 once directly on the glass. Ive got a rheostat but ive never used it because it never got hot enough to even use it. Ive tried letting just uth run by itself all day while im at work still never got up above the 82 83 mark and then the rest of the tank is mid 70s