Just rec'd my TF100 yesterday and I did all of the test yesterday and then again today. Then I took a sample of my water to a pool store by my house and had the water tested. They have some sort of electronic tester that is connected to a computer. I'm getting some very different results and I'm not sure if i'm making a mistake or if the tester at the pool store is off which I wouldn't think since it seems pretty high end.
The two that are off the most are FC and TA
TF100 FC - 7.5 vs. 5.1 from store
TF100 TA - 140 vs. 80 from store