This week my beauties feel better. I have finally figured out how to fertilize them without hurting: the first day watering with half of nutrients the second flush with PH-adjusted water. Spray them with magnesium sulfate solution (1 gram per litter) from time to time.
Also I applied LST this week. It seems to me that I have done something wrong because they look too bushy. I probably have 2 weeks more two correct it.