cannot get my free chlorine to move

[wendy]

HELP anyone... this is the second year in a row that I cannot get my free chlorine level to rise. I have drained at least 12-14" of water added new, my PH is 7.5 Total hardness 360 Total Chlorine 4.5 (high) free chlorine 0. I added liquid chlorine, do I continue to add liquid until I "break" this chlorine lock... the pool itself is crystal clear but this is frustrating since I spent all last summer making trips to the pool store and less time enjoying the pool. Any advice will be appreciated.

[chem geek]

Do you know what the Cyanuric Acid (CYA) level was when you closed your pool? Did you "let the pool go" over the winter not adding any chlorine to it? If your CYA level is lower now than it was when you closed the pool, then soil bacteria could have converted some of the CYA to ammonia. You can get an inexpensive ammonia test from a pet/fish/aquarium store. It will take an FC cumulative amount of about 10x the amount of measured ammonia to get rid of it.