Okay, here's an update.

I tested the water this morning (it's been running since about 1:00 am with the heat on), after having superchlorinated it beginning Wednesday afternoon (it would have finished some time early in the day yesterday). The chlorine levels are FINALLY at the high end of normal - around 3 ppm. TA has continued to come down slightly to 150.

The bubbly haze is less than it was, but still noticeable on the shallow end. I'm developing a new theory. I may be crazy, but I swear my sand filter sounds different -- noisier. When I look at the sight glass over the valve on the return pipe -- located BEFORE the water enters the SWCG -- there are air bubbles. I wonder if the guy made some adjustment to the sand filter fittings or something and that somehow air is getting into the system somewhere in there. Could this, combined with the natural "carbonation" that occurs in the SWCG itself, be what's causing this haze??

-- Jody