fix a leak

We've moved in to a house with 20000 Salt water pool/spa, plaster, Pentair Intellichlor IC-40, Intelliflo, Pentair heater , auto-fill that was built between Nov 2017-beginging of 2018. Since we've never owned a pool haven't done a separate pool inspection. Noticed low salt red light, poured...

I wrote about this 1.5 seasons ago (Pool leak mystery: help me create a plan of action please....), finally have a new update.... Background: had pool replastered. Before doing so, PB did pressure test of all plumbing lines, which cleared. When we bought the house, main drain was plugged, pipe...