Just started owning a 25,000 gallon pool this year. Tried to follow TFP method, but was having lots of trouble getting chlorine to stay in. Then I got mustard algae which I was warned I would probably encounter 1-2 times per season around here. I went to the pool store to get some copper-based algaecide (as the guy who gave me the pool orientation recommended) and the pool store guy convinced me to go with sodium bromide instead (somewhat ironically, he warned that the copper-based algaecide could turn the pool green if I wasn't careful) along with some quick shock aka Sodium dichloro-s-triazinetrione. So I added the bromide and quick shock and that seemed to help, but I still couldn't get chlorine to stick. I tried adding stabilizer to see if that would help, but it didn't. I was still having ongoing algae problems and complete lack of chlorine problems. I continued to use the quick shock and another 1.5 lbs of bromide. At the beginning of this week even the quick shock was having trouble controlling the algae.
I figured I really needed to SLAM the pool, so I tested the CYA and it appeared to be over 100ppm (I realize now that Quick Shock was upping it). So I drained 40% of the pool, refilled, retested and CYA now seems to be at 30ppm or possibly even less, which was not what I had thought it would be by my calculations (was aiming for around 60ppm). I went ahead and tried to start SLAMing the pool with 6 gallons of 8.25% bleach yesterday and the next day I still wasn't registering any chlorine, and there was algae in the pool. I take it there must still be bromine in the pool? I have added about 3.5 pounds of it in the last six weeks or so. Between the bromine, cya, mustard algae, and failure to get any chlorine to stay in the pool, I'm at a loss what to do, please help.
CYA- 30 ppm