Lichtstress?

Maybe, a component of fertilizer is too high, but does not look like light stress. LEaf symptoms are not discrete. You'd want to see how this progresses before reacting to it. as of yet, too little information to diagnose with confidence.

Looking fantastic Hexa, rapid growth on the big one! I wouldn't say light stress no, all the water that goes into the plant must come out of the plant, it is a cycle, In plants, water movement from roots to leaves, driven by transpiration (water evaporation), relies on the cohesion-tension theory, where water molecules stick together (cohesion) and are pulled upwards through the xylem, creating a "tension" or negative pressure, when a leaf starts to wrinkle ever so slightly like its been in the bath too long, its just a indication the leaf has a little more water stored in it than is normal for whatever reason, maybe RH% peaked high for a few hours. IF you added 10F and dropped 10-15RH%, she would start to erect everything rigidly and look like she was praying. More transpirtation = more suction force = more water movement = more nutrient uptake = more stress. If you dropped 10F and added 10%RH% she would droop barely grow as photosynthesis would barely happen, meaning no suction is created through water cohesion. Slighlty downward tips say to me, turn up the transpiration 1-3% (increase water usage through stomata) to increase pressure. But honestly, your plants are looking great. Maybe bump the temperature up a degree or two to encourage a slight boost to transpiration if tip slanting down bothers you. There is no right or wrong; all that matters is you grow! Keep doing what your doing, look forward to seeing this genetic flower.

Doesn’t look like classic light stress – more likely mild overwatering or early N excess. 60W at 30 cm shouldn’t cause leaf tip droop alone. With 2 L every 4 days in 12 L pots, roots might be a bit too wet. Let them dry out more and watch new growth.

I also don't think it's light stress. If it's just the new leaves, don't worry too much; if it gets worse, check the runoff, it should be between 5.8 and 6.5, and the EC value shouldn't be over 2. If it's outside these values, just water with plain water. Otherwise, they still look healthy. Wait a few days to see if it gets better.

I wouldn't bet on light stress. The leaves look very dark, it could be too much nitrogen. Maybe try cutting back on the fertilizer. It could also be watering, do you water based on pot weight? But overall, the plant looks good 😋

Hey there the plant is looking very healthy I don’t think there is anything to worry about you might be slightly over water causing the leafs to downturn but I think your fine honestly don’t worry at all your doing great