Asking for some ideas.
We have a concrete salt water pool; the ph normally tests above 8.2 and while i can adjust it to the 7.2-7.5 range with muriatic acid, the adjustment is short lived. Within 2-3 days it has climbed back up again. Other test results using the t-100 kit are: Chlorine 3-4 ppm, ca-275, cya-60-65, total alk -180.
So i have 2 questions: Why does the ph keep rising? Should i use some other acid to try lowering the ph?