Hi, John,

It sounds like you don't have the bleachcalc....download it from any of mwsmith2's posts.....it'll calc Chlorine, pH, CYA and make it easy for you to put in accurate doses.

Next, I would bring down the pH. use the bleachcalc and aim for 7.4...you'll get pretty close if you measure accurately. pour it in front of the return jet...don't put it in the skimmer. (everything else can go in the skimmer)

Simultaneously with pH, I would add enough CYA to get to 30-40 range. The container will tell you how much to add.

If you get those in this afternoon, I suggest you bring Cl up to around 15 or so at dusk....it'll be most effective in the dark. If you can, test again before you go to bed and bring it right back up to 15. Tomorrow morning same thing. Repeat this daily (if you can test and add during the day as well, that's even better) until your Cl loses less than 2ppm overnight.

Adding polyquat to this regimen will hurt nothing and may very well be what you need to finish the job. Without the above steps, I'm not sure you'll have much luck.

I have no experience whatsoever with Sodium Bromide so I cannot comment.

I hear your frustration, John, but my money is on you ending up the winner....not mustard algae.