Well, it depends on how humid your home is to how many holes you have. I have about 32 holes on each long side and 20 holes on each short side. Humidity in the room's usually 40-50ish %, and the humidity in the tub's 55-62%. That setup is for a ball python. Heating is pretty much the same as a glass tank, except you might not need as much. A section of 3" Flexwatt on a thermostat set to 83 should be good for tubs up to 41 qt. or so, but from there you might think about getting 11" Flexwatt. Keep the water bowl far away from the heat, though, as it may create too much humidity in the enclosure.