Just got back from traveling over the weekend...can't say I completely followed the electrical discussion about using the AUX circuit at 120v for the SWG. But the concern I had about using the AUX (circuit #3 on Mode 2) was that I'd have to be careful to coordinate the AUX on schedule to never be on when the pump was not running at all, based on the emphatic warning in the SWG instructions noted above that say "Wire the Aqua Rite to the LOAD SIDE of the filter pump timer. It is very important that the Aqua Rite is powered only when the pump is running." If I used the AUX circuit, I'd be one mistaken time setting or an incorrect on/off button push away from violating this warning. Not sure what the issue behind the warning is, but as an engineer, I'll respect the thought that went into it!