I'm one of the many who inherited a pool with MASSIVE CYA when I moved in.
After several partial drains this past winter and trying the bio-active reducer (which didn't do much and ended with mustard algae on steps)
I finally got it down to a "manageable" 70 PPM.
Tuesday I started the slam.
Brushed every day, tested 2-3 times a day, ended up adding about 39 gallons of bleach.
got lots of funny looks/questions at the various grocery stores buying 12 gallons at time lol.
Finally this morning the FC was still above Mustard shock (45ppm FC) and to my delight
the CC was .5 (it had been 3.0 & 2.0 every day this past week.
The instructions & help here was paramount to the success. I was very nervous about
it getting finished in time as I have an open house to sell my home next saturday and
have scheduled plumbing/pump repairs for monday to fix a few leaks and a non functioning