Upgrade from plaster to tile: now white substance leaching out of grout lines

Entire pool was resurfaced with tile over plaster to minimize pool surface maintenance for the long term. Pool is a solar heated (May-Sept) saltwater pool in Sedona, AZ with Pentair chlorinator. The local (city/community based well) water is very hard. The work was done in October and we could see the beginnings of the stalactite-like formations on the grout started in December. The work was done by a very experienced tile person in the local region but probably does not do many saltwater pools. The pool was built around 2007. The plaster was not in bad shape but wanted to stay ahead of the eventual plaster to pebble/other replacement. Now we are very concerned. We do not live at the pool full time and are not there now.
The pool is maintained by a combination of strips, test kit and occasional high end in-store professional check. With the chlorinator it is always a task to keep adding acid on a weekly basis in the summer months when the chlorinator is on. Chlorine tabs during the winter months. We did not add anything to make the hardness "in-spec" initially because it will quickly become overly hard and have to empty the pool. Here's the current readings from the tile person who manually removed the "formations" but has never seen this level of this phenomena before. He said he has seen it happen a few times but it is in just a few places in a pool rather than a couple hundred. There appears to be no more exacting understanding of what is going on, thus our post to TFP. The readings were taken the day before our weekly pool guy came to service the pool. FC 0.9, TC 1.2, pH 8.1, TA 123, CH 218, CYA 66, Phos 331, iron 0, copper 0.1. Back on January 12th I took it to Leslie's and reading were FC 1.5, TC 1.74, pH 7.8, TA 131, CH 95, CYA 47, Phos 49, Salt 3150. I added salt in March and it is now at 3500. You can see the Hardness is quickly ramping up. Prior to the tile rework the hardness had gone up to over 800. In the summer the pool temp is set to 85 degrees and is only at that temp for a few hours per day. Does this help? Hoping to find a pool tile expert who understands tile being put onto plaster. The plaster was not removed and not having to hammer out all the plaster was an attractive benefit of the tile install as recommended to us by the tile installer. The pool was installed on clay and we have had issues with settling and broken plumbing so being gentle on the pool for resurfacing was attractive to us. Thanks for the help!