controller choices
 

I am looking for a good reliable controller that can do two things. 1) Control my heater in my sump 2) hook up to a sensor to top off the water in the sump. I am not familiar with these devices at all so I have no clue on which ones are good or not. As idiot proof as possible would also be good. Thanks. Any suggestions or ideas would be helpful.

I have an AquaController Jr that controlls all my lights -- HQI, T5 actinics, moonlights, sump light, HEATER, chiller, et al.
There are many many types of Auto Top Off devices. Check out MD or Premium or Drs F&S, plus there are websiets like autotopoff.com that will do the job. I use the JBJ ATO and it works just fine. I have it connected to my Kalk Reactor. It has two sensors, just in case.

You can also get a heater with a controller for less money than a ful fledged controller.