The ATU-PRO is as foolproof as you can purchase
here is a few scenario's that have been reported on reef sites on other brands of ATU and what the ATU-PRO does if it happens.
1. float physically jams because of a snail or similar
2. float fails electrically
3. float drops into the tank
4. outlet comes adrift pumping water outside the tank
5. reservoir runs dry (possible pump burn out}
6. pump gets jammed
7. R.O. reservoir "dumps" its contents into the aquarium
ALL THESE ISSUES SORTED!
think thats pretty well covered it (and if I havent, let me know!)
in every situation above the pump will shut down after a time period set by yourself with the options of 5, 10, 20 or 60 seconds.
includes the programmable controller, infrared sensor and mount (the need for a twin float doesnt apply as timer will shut down in a fail situation)
low voltage pump with a height of 1.3m along with piping, and of course the power supply.
NOW FITTED WITH AUDIBLE ALARM!
so something fails, what happens?
in a nutshell it shuts down! so the top-up is inoperative until you come along and reset it, indication that it has shut down is via the pump LED starts flashing, the audible alarm will sound for 1 minute then give a beep once every 2 minutes until the problem is corrected
reset is a simple push of the button, if the cause of the fault is still present then it will go back into alarm state
BONUS - Anti-Wave - many are familiar with the pump switching on and off every time you stick your hands in the water, or the same things happens if you have that powerful wave maker powerhead.
this is addressed by a 3 second built in water level delay activation, in other words the level has to be "LOW" for 3 seconds before the pump starts, as soon as the float reaches a "HIGH" position the pump stops immediately.
BONUS - Memory - that preset time you set up stays unless you reprogam, it is not lost on power failure!