I subscribe to the theory that heater failures are the number one cause of tank crashes. I've had heaters fail on, off, trip the GFCI outlet as well as the homes 15a circuit breaker. So I run two heaters, on two different completely independent heater controllers, each on its own power bar plugged into separate GFCI outlets. I wish I could also have the outlets on separate circuit breakers, but currently don't the ability.
I bought a pair of W3230 heater controllers on ebay.
I then mounted them into 2 gang wall box / or standard light switch and cover. I have 300W Finnex heaters with no internal temperature control. To wire the switches inline, I cut the ends off the heaters and stripped the wire to mount directly to the heater controller. Then used a 6' extension cord to complete the wiring from the controller to the power bar. Again cut and stripped the ends to mount directly to the controller. Mounted it all to the electrical portion of my equipment stand and set the program. I wrote the functions of the menu's on the cover for easy reference.
It may look confusing, but it's pretty straight forward. There are three wires from each outlet. Black, white, and a green/ground. The exact same black, white, green from the heater. Then two more wires for the temperature probe that are already connected.
These particular controllers obviously switch the heater on and off, but also have an overtemp function that will cut power to the entire controller unit if the limit is reached. If that fails, the reef keeper is set to turn off the outlet in the power bar 1 degree over the temperature controllers. Now if one heater fails off, I have a second heater. I also have 3 layers of protection for a heater that fails on. I also have redundant sources of electrical power, at least back to the main circuit breaker panel.
The total cost was ~$20 (not including heaters) and took me about 4 hours to complete. It would have taken less time, but my OCD to keep the wiring neat took longer.
