Hm, 500# of salt? That seems like a lot. That would add 1500 ppm of salt, which with even using your lowest number, would put you at 3800 ppm, which sounds kinda high to me. What ppm are you supposed to be running at?

Having your CYA at 100 likewise sounds high. I'm in Houston, tx, run mine at 40 ppm and have no problems. Your alk looks a touch low, I'd aim for 120 or so.

Michael