The city water authority doesn't list it on any website. Do you not think a pool store would know the CH in tap water? Do you really think they'd lie about it?Pool store? That could be big trouble. How about the city water authority?
Anyway, it looks like zero is the correct reading. I just called the All American Pool Company in Lemoore and was told that city water, depending on which part of town, will run anywhere from zero to 50.
That confirms The Tank's reading as correct and that he needs to raise the CH in his pool.