Quote Originally Posted by waterbear
The letter was downloaded from the "for professionals only' section of the Jack's Magic website! It is the form letter (with the Jack's magic logo on a blue background on the left side that starts "Dear Pool Owner" and goes on to talk about some of the Jacks Magic products including Blue Stuff, Purifiber, Purple stuff, and seaquest test kit!

YES!!! This is it! I thought it seemed like a sales pitch since it sounded so "generic". But, I wanted to make sure. My company didn't tell me that I had to use the product to maintain my warranty, so I was a little confused. Maybe they have some kind of marketing program going with Jack's Magic company.

Anyway, thanks to you both for the info. I was just out adding bleach and brushing when I noticed some new spots, so there is definitely something going on. I will try the vitamin c after the bleach circulates through and report back.