On the 7th day, not enough water came out of the filament to turn on the pump & the nighttime dewpoint matched the night before.  All the water was taken out of the filament that this method could take out & very little new water seemed to leak in.

Of course, the on point was within the error bounds, but it was close enough to consider the reaction done.   If the inside dew point rounded high, there would not have been enough difference in dew point to cause any significant removal of water. It was decided not to upgrade microcontrollers to get a more precise dew point.  

Also the outside dewpoint went back to normal.  It might have finished sooner if an offshore flow didn't create 2 exceptionally dry days.  The normal humidity will probably leak in & cause the pump to turn back on over time.

The next step is to wait for peak heating to draw out all the water again & transfer the PLA to another enclosure with desiccant.  The dehydrator's next task is drying PETG.  Because of the damaging effects of UV, there's no other choice but to store dry filament in bulky containers containing desiccant.  The lion kingdom couldn't find any airtight bags smaller than giant tupperware.  The dehydrator needs to be moved away from the window, sealed by valves, & filled with desiccant to store filament.