PH question

[waste]

Penny, nice to meet you!

With the exception of the CC being ~ 1ppm and the alk being slightly low - the numbers look good. The 'adjusted alk' takes into account that the cya registers as part of the total alkalinity, so is adjusted for it. 4 lbs of baking soda should get you to 80 on the 'adjusted' reading, which is fine (usually).
The ~1ppm combined chlorine is more important (IMO). FC + CC = TC, so you've got something in the pool that the chlorine is attacking, you need to raise the FC enough to kill whatever's in the water and keep it raised until the CC = ~0.
I think that you've got more than enough cya in the water and should stop using the tri-chlor tabs, use bleach at night to sanitise your pool, the tabs just increase the amount of chlorine you need to keep in the pool, and drop the pH.
7.2 for pH is fine, but you don't want to go any lower.

Please realise that I'm not a chemist but the advice I've given comes from years of experience and years of reading this forum

edit: I will always differ to Evan on questions like this - I'm just such a slow typist that his response - and yours (!) beat me into the forum - edit