PersianGreenthumb

They are stretching, seems they are not getting enough potency from those lights (too far apart from the plants, or simply very low power) Also be careful with over watering and check if soil is not compacted, better spongy. The bigger ones seems ok, but I see some that are maybe suffering some nitrogen defiency. Keep going!

I will need more information about your grow but it looks like your having a potassium deficiency. Sometimes the first symptoms of a cannabis potassium deficiency look a lot like nutrient burn. One difference is the edges of the leaves will also start turning brown, where nutrient burn usually only affects the tips. And unlike with nutrient burn the leaves of a potassium deficiency turn yellow in the margins, especially near the burn edges. Hope that helps good luck to you 👌🏾

Never grew this one but the twisted leafs lead me to think something went a bit wrong with nutrient and water

Check your run off PH . If it's massively out you may have a nutrient lockout. Feed extra volume at the same pH To correct until it's back to a reasonable level. Also I'm not a big fan of the blurple lights . Get more for your money out of a quantum board. Even Mars hydro do some good lights now . Good luck 🌱

I think it may be seeding. :/