Mack&Crack, Apollo BC an Blue Moby

So many growing points and they promise me lots of the prettiest and densest buds. I'm so excited! One of the Mack and Apollo are showing signs of light stress. I reduce the lamps by 10% and move a little farther away. Strangely, the other Mack is doing just fine..... Also the tips of the leaves have started to burn a bit, although I follow the table unquestioningly. I don't really care about that at this stage. My assumption is that the pH perfect technology is lowering the pH too much for calcium and magnesium assimilation (their assimilation threshold is 6.0). I contacted AN support with this question, to which I was told not to worry. I in turn added intermediate watering with increased pH value and added Calmag.