How hot should hot spot be right above the heat tape?

I just installed belly heat flexwatt in my rack with a thermostat. What should the temperature of the tub be right above the heat tape? (Hot spot)

Personally, I aim for 90 degrees. As long as your ambient temps are good (around 80 degrees), this lets your BP choose the best way to thermoregulate itself.

The room temp is around 70

The tub ambient temps. Unless the snakes are hanging out loose in your room. :)

No more than 95 degrees MAX on the floor surface of the tub. (area your snake can touch)