I don't think it is a good idea to run soo much stuff off one thermostat. If that one fails, that's a lot of animals it will affect. I know people that have had one of the good digital thermostats fail and lost over 20 snakes that were controlled on it.
My personal feeling, and what I practice, is one thermostat per cage, or per rack. I will actually be replacing a 41qt. rack I use for small adult male Boas this year so that I can get something where each bin is separately heated and I can run each snake with a different thermostat just like my full size cages.
You can never put a price on a life, and that's what is depending on the equipment we use.
Herpstat PRO is $320, divided by the 4 independent outputs, that is $80 per thermostat equivalently. Can't be beat for price or options, and it is a digital proportional thermostat, which is undeniably the best option.
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Gilbert Boas
The Boa List!