Well, I overfed them or they want calmag very much.
Next day after watering with nutes purple spots appeared then turned into dry brown spots.
But they are getting fatter.
Also I started to give then 2lt of water each instead of 1,5.
Also one day it was very very hot, I forgit to turn on the aircon so temp grew up to 32 for several hours. When normally it's 22-24.
Next time I should be more cosious with nutes.