It was running close to 12 hours. The CPSC36 has a built in test that seems pretty accurate. I tested it last year against a strip and the results were approximately the same. After a couple hours the unit reported 2700 ppm and then about 8 hours later it was still reporting 2700 ppm. I didn't get home in time to add another bag this evening. I'm going to work with it all weekend. I'll get the salt up first. So far it looks to be 100'ish ppm per bag but I'll take it slow so I REALLY get a good estimate.

Yes I am interested in how to speed up lifting the stains!

Thanks.