I saw a new doctor (an MD even!) today who actually will listen to a patient who believes he or she has LOW acid... I gave her my health history with my blood work labs, scope reports, etc and one thing she did say after I told her I had my gallbladder removed: Gallbladder trouble is often (but not "always") related to low acid.

I told her I'm using ACV...she asked how much and how often, which I told her was about 2 Tbsp. at each meal...
Anyway, she said since the gallbladder was removed, digestion may not happen as well and she advised to take Bile Salts. She also advised to take digestive enzymes that contain HCl. And she also said to take Magnesium Malate and Aloe to soothe the digestive tract.

These might be options to discuss with your own doctor if you feel low stomach acid is your trouble...BTW, low acid displays many of the same symptoms as too much acid.

Hi, I don't notice sudden reflux, but have excess saliva that tastes acidic. Could one still have an acidic taste with low acid?
I still have 'rocks in the chest' after months on PPI's
Thank you

Yes...
I use vinegar when I feel symptoms of reflux and almost instantly, the symptoms go away. Some of the things I feel are, like you, too much saliva, tongue feels like it's burned, and, to use your phrase, "rocks in the chest." You can have all of this and have low acid.
Not a lot of doctors these days are paying attention to low acid. I am amazed at this. I would say by all the ads in magazines and on TV and radio, that humans just one day started cranking out HCl in their stomachs like crazy... That just doesn't make sense though. Every other process in our body tends to fade over time but, magically, our stomachs come up with the ability to do more???? Don't get me wrong. I know that there are people with the problem of hyperacidity, but that's not as common as stomach acid levels diminishing over time.