I tested it three times in different places in the pool to make sure. Although I do chlorinate with cal-hypo I've never had this problem before (or even remotely close). Sand filter has been running 24X7 for four days, which is usually enough to clear the water. I became suspicious when the water went milky white (light gray?) with no change in two days.

Pool info: 20 X 40 IG vinyl hopper (3 and 8 ft. depths) - 33K gallons

Currrent levels with Taylor K2006:

FC - 11
CC - 0.5
PH - 7.4
TA - 70
CYA - 0
CH - 1900 (!)

Other info: New liner installed last year with refill from hose (yes, it took two days). Fill water tests at CH 200. Everything was fine when closed, and I don't think the cal-hypo used for opening accounts for this level in the pool. I'm going to do the lime softening bucket test to see if that will help.

Any ideas what could raise the CH up so high?

I follow BBB so no other gunk has been added, although I may have made things worse by adding baking soda to get the TA/pH up. Thanks in advance!

Tad