Apex will controll everythig..tank gets to hot turns off the heater if the heaters malfunctioning, if it still gets to hot throws a fan on,if it continues to climb itll turn off your lights and diffpumps if you want it to. can control different powerheads like vortech, and dimmable leds. Like torx was saying you can have them control ATO so theres no need for a sensor. It can send you messages and emails alerting you if something isnt right withyour tank, for example if you jave overflow sensors for the apex youll get sent emails telling you theres a leak or some sorta overflow, and set off it own alarm to let you or someone else in the house know something is going on, hook it up to the net and you can access it from your cell and change w.e you want on your tank with the touch of your cell. Its a great investment, especially for stability in a tank IMO.