. . . membership upgraded.

Eric, please note that -- though there's no easy way to lower CYA -- there is an easy way to adjust to high CYA levels.

1. Read the Best Guess and Test Kit pages linked in my signature block.

2. Get a K2006 test kit, and find out what your *actual* CYA level is.

3. Use bleach or cal hypo to operate your pool at the appropriate chlorine level.

Points to remember:

=> "Chlorine lock" is a WAG explanation, generated by pool industry types who do not understand the CYA / chlorine relationship.
=> Test strips are horrendously inaccurate at measuring CYA levels, regardless of how you read those strips.
=> High CYA *plus* high chlorine allows you to 'store in reserve' a LOT of chlorine. With CYA levels > 150ppm, you can operate your pool by raising levels to 20 ppm or so, and then letting them coast down over a week's time.