Funny thing is that my old self (~20 years ago) would have immediately added an alkalinity supplement to balance that calcium reading. LOLThe Hanna calcium checker gives folks more problems than most, and it is freakishly sensitive to calcium in the blank, requiring distilled water to be sure calcium is low enough in the blank to not give false low readings in the tank sample.
My #1 rule in reefing is nothing good ever happens quickly in a reef tank.