I hate being Color Blind - Strange Test Results

[CarlD]

Wow! With a CYA of 100 and a pH of 6.6 you are DONE using tabs for this season.

You are wise to add LESS of baking soda than you think you need--you can always add more. Once your T/A hits 80, stop add the baking soda.

Dumping half your water and refilling isn't so bad with a 6,000 gallon pool--that's only 3,000 gallons, about the size of 15' donut pool. Your pH will go up and your CYA will be cut in half--50ppm is a fine number to work with.

You need to get a proper FAS-DPD drop kit so you can measure yourself. There are 2 I know of (but I think Poconos knows a 3rd).
1) The TaylorTechnologies.com K-2006 or K-2006C kit (the latter has larger supplies of the reagents).
2) Lesliespool.com (the on-line site of the pool store chain) has their Chlorine FAS-DPD Service Test Kit, which is basically their re-branded version of the Taylor K-2006

Other than the pH test, you should be able to run the others--and, for the T/A test you can have someone tell you when it goes from green to red if you can't see it.