hey there Timbarin, it looks like magnesium deficiency to me because of the yellowing between the veins but affecting even newer leafs not just older leafs, this is actually due to light stress from before, plants need more Mg with strong lights and heavy light schedules , even in soil the truth is that with these kinds of genetics you need extra cal mag, you can even make a spray with it and use it until second week of veg. Hope this helps ! đ