Okay, an update:
FC=5.2
CC=0
pH=7.8 (maybe 7.9)
Alk=90
I turned the SWG down to 40%, as it was pushing up into the 7.x range when set to 60%. Initially, when set to 40%, the FC dropped into the 3s, so I extended the run time from 6 to 8 hours. It’s been a week or so and seems to be settling...