Best ATO for Pico reef?

[mjw011689]

Like title says, whats the best option for an ATO on a 5 gallon tank? specifically the fluval evo 5. Not sure if there's any good spot to put the level sensor on this one without being super visible.

 

[blaxsun]

Once upon a time I bought one of those gravity fed adapters for a 1.0L water bottle. Worked great for my 12-gallon tank.