I have a spa that overflows a rock wall ledge into the pool. In the mortar between the rocks I am noticing what appears to be white calcium scaling? Scrubbing with stainless brush removes a small bit. (very hard scrubbing.)
Whats the best way to remove/prevent this?
Current Test Results:
PH=7.8 (Added 12 oz of acid to drop this to 7.5ish)