Low CH in AG pool

[mbar]

You don't need calcium in a vinyl liner pool, so you are ok - you didn't post your cya (stabalizer). The cya is what determines how high you need your chlorine. The alkalinity and ph are good.

[kjmelak]

I knew I forgot something!

Last time I checked on July 14th ( I ran out of reagent!), CYA was 40.

I stopped using trichlor pucks a few days ago because I didn't want the CYA level to rise much higher. I am now using bleach.

[mbar]

Then your numbers are great!