Would I need two thermostats, because i would need to heat my cold side to 80ish because my room is only 72 and then i know i would need one for the hot side to get it to 90ish, but would i need one for the cold side or can i just use one had set 2 different temps?? How does that work, because i want to get the herpstat II but if i can get away with one insted of two that would be nice!!! ( they are soooo pricy) i just bought two Repti-Temp 500R and waiting to hook them up because i still have flex tape coming. So do i really need 2 .