The marine pac 3 will work with any of the ATU-PRO3 AUTO TOP UP from reefloat with the nano pipe and fluval edge mount.
The ATO units reefloat makes have a programmable run time, set this to maximum.
The MAME ATO unit is not compatible with the marine-pac 3.
Currently no other ATO units have been tested with the marine-pac 3
Recommend units are the ATU-PRO3-12 (includes a 12 water tank) or the ATU-Pro3 (supply your own water container)