Sorry. I'm not going to do this.
You're a pharmacist; you can read the stuff here, and particularly the stuff Chem_Geek has posted in the China Shop, here, and in "The Deep End" at Trouble Free Pools. Make up your mind about who's credible, and who's not. You have the training to do so; you don't need our help to make sense of it, and lots of other people who come here, do.
If, and when, you decide that it would be a good idea to let us help you with a recipe, say so. But till then, please work on it yourself.
But, there's really no point to going back and forth between us and the pool store; it's a waste of time for everybody. It sounds like you're saying their advice got you where you are, which would seem to me to point to an obvious conclusion. But maybe not. In any case, you're the one who has to reach that conclusion.
For what it's worth, I'm not saying your pool guys are bad people -- just wrong. You're a pharmacist -- you know better than I how profits drive training and the information flow: pool store guy chemicals vs physician prescriptions . . . it's a matter of degree, not kind. If you've been a pharmacist long enough, you've seen GSK and others laughing all the way to the bank, as the 'save the ozone layer' laws drove the generic asthma drugs right back into their patent jail.
GSK makes billions, screwing up asthmatics lives; BioLab makes millions, screwing up pool owners pools . . . and the gullible believe them when they say they really just want to train you in better pool care, or patient care.
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