zepplockso $60 for a controller (http://www.etcsupply.com/ranco-etc111000000-digital-temperature-controller-p-86.html)
and then buy *any* 200w thermometer and set it to max?[/quote said:
Yup that is the controller. It comes unwired, so all you need to do is pickup a decent 16 or 14 gauge extension cord at Osh or Home Depot, cut it in half and wire it up. Or for $75 they offer a prewired option. http://www.etcsupply.com/etc-prewired-c-38.html If you buy the unwired one and need help just come by my place in San Ramon and I'll help you get it hooked up.
If you can I would start with two heaters but if budget does not allow start with one. The most important thing is the good controller. I would set the thermostat of the heater itself a few degrees above what you set the controller. Say if the controller is at 78, set the heater at 80 so that in the rare chance that the controller sticks on (I have still never heard of a ranco doing this and I use 10 of them between all my systems for 5+ years) you will still not cook your system. The ranco should be within a about 0.5 degrees of being perfectly accurate while the thermostat on the heater could be off by up to 3-5 degree depending on brand. So when you get things setup just make sure the heater thermostat does not click off before the Ranco does.
If you go down the two heater route I would just check that both of them are working every 3-4 months or atleast right before the cold season. I run 4 Ranco's per tank on my systems. Each pair of them wired in series so that both have to say on before they will click on. This way I have no chance of cooking my fish but since things "fail open" or off with my configuration I run a second pair set at a few degrees lower just incase the primary pair fails. I run the second pair on a second GFCI just incase also. My systems are quite large though and just never want to deal with having my tanks cooked. Good luck. -Chris