Just plastered with mini pebble. Filled 2 days ago and just added some acid. pH shows at least 8. CH is 90. ALK is 110. When performing the acid demand test, one drop will send the test sample down below 7. I've never seen this before in a stable pool. I'm running the filter and brushing twice daily. Pool contractor added some chlorine...I believe it's at about 3. I've never re-done a pool before so I don't know if I should be chasing pH or let it go for a few days at a time.