TC vs FC... am I about to turn the corner???

Opened 18x36 26K IG 9 days ago and found no CYA. Added ~8# CYA, adjusted Alk and PH and have been feeding bleach in ~10PPM quantities early AM and late PM nonstop while running the pump/filter 24x7. Iit's getting to cross the expense pain threshold.

I had been running ~0 FC and 3-10 TC since opening. But tonight I am registering a slight FC reading and the TC has dropped to 1 (this AM it had been reading ~5PPM). I also noticed the PH has dropped a bit (it rained this past week and the rain here is very acidic).

So I'll adjust the PH again and continue with the bleach but the CC dropping... is it a sign? Have I finally turned the corner against the chlorine eating beast? What is the "life cycle" of Chlorine? Does it actually go from FC to CC? If so then what?

On another note... I think I figured out where my CYA went. Back last Fall, the Northeast had a weeklong downpour (a hundred year storm). Roads, basements, creeks... flooding was everywhere. I don't recall the final tally but I recall total rainfall approaching mid-high teens. I googled a link here...

http://www.foxnews.com/story/0,2933,174298,00.html

Since I have an overflow/level control drain in my pool... I suspect that my pool water simply got diluted to a considerable extent with the rainfall.