7.5 pH is quite alright. Once it gets up to 7.6, I would start thinking of adding no more than a pint of Muriatic acid, and test after about 6 hours circulation.

Once you get your salt level checked without using a conductivity meter that pool stores like to use, you can get an idea of what to do. I would still trust the PS234 salt over a pool supplier test any day. The instructions are fairly straightforward.

Hope this helps.

Pat