I'm opening my pool. All going well, added enough beach to clear it up (~12 gal?). pH about 7.5, TA about 140 (a little high, but not too concerned). Basically 0 ppm chlorine at the moment (wife is bringing bleach).

I went to test my CYA using the K-2006. I can't get any reading to speak of! Last fall I was reading 100+ ppm - enough to make me think maybe I should partially drain and refill the pool. Now nothing?

Any suggestions? I don't want to start throwing chemicals at it, particularly not CYA. The test kit is probably about a year old, but I wouldn't have thought it would go bad that quickly (it was stored in the basement over the winter). I can certainly go to the pool store this week for a water test...

Barring further insights, I'll plan to bump the chlorine to about 10 ppm tonight, check it tomorrow morning and then again tomorrow night. If it is stable overnight but falls off with sunshine maybe I'll believe the 0 ppm CYA reading...