First - my bad. The 1# package of 62.4% CalHypo never claimed to shock a 16,500 gallon pool, it was 1 package per 8000 gallons. I got the 16,500 number from my OTHER brand of CalHypo, the 73% brand.

Now for good news. I added about 2# CYA yesterday, half about 1PM, 1/2 about 7PM. The pool actually held some Cl through the sunny day, but still only measured 1 total and less than .5 free at 8PM. At 8PM, added 1# of 73%CalHypo.

Total Cl added yesterday was 1# 62.4% CalHypo in the AM, 546 oz 6% bleach at 1PM, when my test showed 0 Cl, and 1# of 73% CalHypo.


This morning's readings show:
Cl 5+ (10+ on the 2x test, maybe 9 on the 3x test)
Free Cl 5+
pH 7.5
TA 80
CH 110

I think we're getting there. Will add appropriate amt of baking soda to raise TA today, as I didn't do that yesterday - already adding a lot of other stuff. This AM, I've already added my last 1# bag of the 62.4% CalHypo which should get me to the 15-16ppm mark.

I've also ordered stabilizer tests - don't plan on adding any more stabilizer until I can test.

I'm anxious to see if that amount of CYA I added yesterday might help hold chlorine today.

Question on the CH drop test: When I did the test yesterday, the initial color was a light pink, rather than red. Today, it barely looked like a pale pink. Adding drops changed the color, but to a very light green rather than a blue. Results still valid?

Thanks for all the help.
Sandy