This is one of the issues with tubs there are very few options to provide secondary heat. The johnson or ranco will work well with the space heater. Sometimes the forced air ones cause spikes up and down when it kicks off and on. I tried one for a while AND FOUND THAT LOCATING IT HELPED A LOT WITH THIS SWING. IN MY CASE I HAD IT QUITE HIGH, THE TOP OF A SHELVING UNIT. Oh stupid caps lock sorry I am leaving it... The unit pointed up a bit it blew away from the snakes enclosures directly, it also mixes the air in the room well.