Should I fertilize already?

so I wait another week, and then I will give 0.5ml Biogrow

No nutrients is needed in brand new soil. At this stage only roots enhancer, enzymes, humic fulvic acids. Make sure to pour enough water when you water your plants. Your roots system is too small for the moment, your roots aren’t using all the nutrients available in the soil. When nutrients aren’t used they turn into salt (NaCl) and the EC of the soil start to raise.

The lite mix usually has enough nutrition for the 1st 3 weeks, after that start applying your grow nutrient at 1/4 to 1/2 strength and see how they respond. Your plant looks like I would expect it to look like after 2 weeks.

do you see that sendvid link not? https://sendvid.com/3h56c2gs also do you think I should give 0.5ml BioGrow now? on 1 liter of tap water? Or should I wait with the fertilizers? Biobizz says 1ml per 1 liter

Your plant should not need any extra feeding during the first 3-4 weeks of life when growing in soil. Starting with half strength nutrients after this is plenty enough feed for young plants, even all the way through to flowering. I find giving half strength nutrients every 7-10 days more effective than giving full strength nutrients every 10-14 days. Cannabis seems to enjoy a gentle constant supply of mild nutrients, rather than strong spikes of nutrients. Hope this helps, Organoman. BTW, pasted links do not work in this forum.