The ambient temperature in my snake room is usually around 72F in winter. In summer it can reach 84F, as I have very large old windows in my room which makes it too difficult to monitor the temperature in the room, which also means controlling the temperature using a source such as a oil heater or even air conditioning is pretty impossible. I also do not have the ability to use a separate heating source other then heat tape simply because of where the room is located and space available. The heat tape does well with providing heat and even heats up the ambient temps in each tub. Using a herpstat, it is well controlled. As your method may work for you, it may not work for everyone else. I am glad though that you found something that works for you!