HouTex,
Based on the plasterers chemical readings, the water is on the positive side of the CSI. It was not aggressive. If you allowed him (the plasterer) to do a No-drain, then your plaster WOULD shows signs of aggressive attack. The point being that you would no longer be able to prove that an "aggressive attack" didn't cause the spotting. You are right, the plasterer will probably fight you on this. He honestly may not know why "spotting" occurs on some of his plaster jobs, and has believed what other plaster people have told him. And of course, he doesn't want to pay for a replaster.
You water chemistry is excellent. As others have stated (I believe) on this forum, a CSI between -0.5 and +0.5 will provide very good balanced water for your plaster job. As you know, the higher calcium level offsets a lower TA. I would also allow the pH to rise a little (7.6 to 7.8), that is my personal preference and experience.
Finally, since your plaster also contains quartz and has a general mixed coloring aspect to it, the spots are not showing up very much (as you stated) and probably aren't serious as such, then I think you have nothing to worry about. The depth of the affected spots are probably only about .5 millimeter deep (the overall thickness of your plaster coat is probably about half an inch). Just understand that you didn't do anything to cause those spots to appear. There is nothing you have done or can do to have stopped this.
Maybe you can take a minute (or however long it takes) to educate your plasterer on what actually causes spotting to occur, and help prevent this from happening to others. If you ever want to puruse this, PM me and I will provide you some free advice and literature. Good Luck.
P.S. I hope Ping reads this too.
Based on the plasterers chemical readings, the water is on the positive side of the CSI. It was not aggressive. If you allowed him (the plasterer) to do a No-drain, then your plaster WOULD shows signs of aggressive attack. The point being that you would no longer be able to prove that an "aggressive attack" didn't cause the spotting. You are right, the plasterer will probably fight you on this. He honestly may not know why "spotting" occurs on some of his plaster jobs, and has believed what other plaster people have told him. And of course, he doesn't want to pay for a replaster.
You water chemistry is excellent. As others have stated (I believe) on this forum, a CSI between -0.5 and +0.5 will provide very good balanced water for your plaster job. As you know, the higher calcium level offsets a lower TA. I would also allow the pH to rise a little (7.6 to 7.8), that is my personal preference and experience.
Finally, since your plaster also contains quartz and has a general mixed coloring aspect to it, the spots are not showing up very much (as you stated) and probably aren't serious as such, then I think you have nothing to worry about. The depth of the affected spots are probably only about .5 millimeter deep (the overall thickness of your plaster coat is probably about half an inch). Just understand that you didn't do anything to cause those spots to appear. There is nothing you have done or can do to have stopped this.
Maybe you can take a minute (or however long it takes) to educate your plasterer on what actually causes spotting to occur, and help prevent this from happening to others. If you ever want to puruse this, PM me and I will provide you some free advice and literature. Good Luck.
P.S. I hope Ping reads this too.