So, our pH is high (8.2+) and so is our TA (120). Pool Calc says to add MA, so I'm ready to buy some. DH goes on a pool store web site that says MA is not for vinyl liners. If not MA, than what? I can't seem to find that same info here, but maybe I haven't looked hard enough. Can someone advise? Also, we are getting ready to close, so have the FC up at 15 for an overnight test. I read somewhere else on this site to wait til the FC drops below 10 to trust the pH test, so I am sort of in limbo right now. Thoughts? Thanks in advance--every time I come here I get excellent help!