Thanks for your replies, I'm a beginner gardener but I'm going to start making a dairy soon. Yes, the plant grows in soil, it is Biobizz Light Mix, it is currently at 4 weeks with two plants and week 3 with the third.
I started with a water pH of 6.3 but after 2 weeks checking the soil which was 5.8 I raised the PH of the water to 6.5. The pH of the soil is now at 6.2
Those three plants are Automatic in a 60x60x180 tent at 150w Mars Hydro TS 1000.
I use supplements from BioBizz Grow/Bloom and TopMax. I added BioBizz Grow 1.4ml/l last time 2 weeks ago, then I saw the problem whit claws and I thought there was probably too much of something. The temperature in the tent is 26-27 degrees and I water it once a day, always checking the weight of the pot, yesterday whit 500-600ml of Ph 6,5 water.