Hello, This is my first grow with BioBizz All-mix supstrate. I't supposed to have nutrients for the first 3-4 weeks. I'm growing under 600 W HPS, having day temp at 26°C, night at 20°C. Humidity is from 45 - 70% depeds if I watered or not. The problem started at second week from germ. The leaves started to yellow between the veins and on leaf edges. It spread from the bottom of the plant upwards. Now they are are all like that. Finally the leaves started to curle. What's wrong and what can I do?