Alright, I'll give you more details, as they came available, so it won't look like a theoretical question.
Pool was closed last winter with CYA= 60. (Frankly, CYA was measured using the Taylor kit only at the beginning of the season. In theory at least it could be lower than 60 at season's end. It won't happen again...)
About two feet of water was drained upon closing, and then, at the end of winter, due to snow fill up, close to another foot was drained.
Pretty soon rain water filled up, so all in all it is fair to say that the pool had a 25% dilution.
The pool is still covered with the winter mesh cover, but submerssion pumps have been working 12 hours a day at about 3000 gph flow rate.
Numbers after a good circulation:
FC=CC = 0. pH = 7.3 - 7.4. CYA was measured at two different pool stores. One measured 0 and one measured 8 ppm CYA. Dilution only should have brought the CYA down to 45.
Bleach was added to reach 2-3 ppm FC. Winter cover is still on.
FC dropped to 0.8 after a few days. CC is still 0. Amonnia = 0.25 (difinitely not 0 and definitely lower than 0.5.)
Based on all these numbers and the pool's history, is it reasonable to say that my CYA was eaten up by bacteria?
Should I expect a large amount of FC to bring the ammonia down to 0?
What is the theorteical amount of FC needed to "burn" the ammonia?
Should it be done before or after adding CYA?
Thank you.