Digital STC-1000 Thermostat Temperature Controller

[Zante]

I use one on each of my larger aquariums. They're excellent thermostats, thinking of getting some more for the smaller ones that also need cooling, like the shrimp tanks and my plankton cultures.
It's no coincidence they're very popular in several fields of use.

 

[JWF]

I copied this set up when I built my second cabinet - http://www.3reef.com/threads/stc1000-temperature-controller-build.113545/#ath