Hi Waterbear and Iggy, thanks for the replies.
To answer Waterbear's questions:
SWG: Polaris Autoclear Plus
Filter: 36 sqft D.E.
CYA: 100 ppm
TA: 80 ppm
pH is quite low, 7.0, but I was waiting until I decided whether to drain out some water or not before I correct it.
Iggy,
The big question...