I am using the Taylor chromate inidcator and silver nitride sold as a kit and recently as I add the reagent the mix (on a speedstir ) starts to become colloidal. Little floating globules of whatever appear. I do eventually touch the milky salmon 'stop' color but the tube looks a mess and if this thing is to be believed my salt levels have not changed since I added salt in Feb. That is despite heavy rain, overflow, splashout. The pool store numbers tend to be a little lower than mine. One said I was off by 1200 ppm though. The SWG's opnion has bounced around with variances up to 600 or so but thats apparently normal. I'm kind of curious what my salt level really is and if I'd know if it was under/over.