I Finally got my TF-100 test kit a few days ago. I did the tests today, then brought some water to Leslie's to compare with their test. They were way off! I got : PH 7.8 and Chorine of 1-2 on the quick OT test. on the more accurate DPD I got FC 2; CC 0.5, TA 110, CH 560; CYA never worked- I could alway see the black dot till the red tipped vial was empty, and cylinder was overflowing. the results from Leslie's were: FC 0.5, CC 0.5 (he said they were barely visible, but >0); TA 80; CH 300; CYA 20; PH 7.4.
I would normally assume I was in error, but with new reagents (never in the sun), and test which are easy to read - color changes after a drop is not very subjective. (I carefully measured each sample and did both tests within 30 min.
I do believe the CYA is low, so I added some. I have questions as to why the drop, But I added them to another thread.