I received Ben's kit a week ago and I think I am in heaven. I do have a few questions on making some adjustments. My Readings today:

8 am - 6:30 pm
FC 4.5 - 4.5
cc 0.5 - 0.5
TA 13 - 13
ph 7.5 - 7.6
cal 220
CYA 100
12,000 gallon fiberglass pool in sunny, hot south Louisiana
Mt water temp runs between 84-86 and I have a small fountain for aeration.
I have been battling high CYA- over 160 begining of May- which I have lowered to 100 as of today by periodic lowering of pool water(12 " at a time per manufacturer) and refilling. Last week I used Metal Out and Stain out to get rid of brown stain that has been on the bottom of my pool since I first opened this spring- stain is gone and of course the day that I used it my chlorine level went to O. I have been adding bleach 2-3 times a day since I stopped using pucks in May and switched to bleach .

This morning after the first reading I added a gallon of bleach. For the last week, as long as I kept my chlorine reading above a 7- I had no CC. But if it drops, the I get a .5 cc- never any higher. I have to add a lot of bleach each day- at least 2-3 gallons a day to keep readings of fc at 7. Here are my questions:
1. Should I shock first raising to 20-25ppm and then add muratic acid to lower PH or should I lower ph .4ppm and then try shocking?
2. Could there be any other reason for my chlorine levels not holding/

I thank you all in advance for any help you can give me. This site is a godsend. I even have made a believer out of my husband because my pool water is sparkling.