Quick one

Hi mate, I had the same problem in a start of my grow, I was sure it isn’t overwatering in my case and after research I found it was a heat stress from my Mars Hydro TS1000, it was just too close, I lifted it up to 75cm from plants and problem was solved, no worries with stretching, not under this LED

Keep working on them. You can help them somehow. Don’t lose your trust in them. They you to be happy for them to be happy. Good luck mate (growing the same strain, I’m just at week 1). Have a nice day and a nice harvest!

There are several issues that could be contributing to the issue. First, dark green foliage and clawed leaves (tip pointing down) that's over feeding, in this case Nitrogen. Second; 0,4 liters of water per day is too much at this stage. The yellow tips, it is probably due a minor element lockout (again because of over feeding). 5 Gallon of soil does not need feeding yet, wait until the plant consumes the nutrients in the soil and shows the first signs of deficiencies, most probably you will not have to feed more than once or two times in the whole run.

Just by looks at the pictures, I'd do the recommended things. Raise your lights to 24 inches. Around week 3 I've noticed more girls take about 1 to 2 cups and are fine. Increase gradually as she drinks. This may take a week or even a few days you'll notice shes drinking fast if she drinks 2 cups in a day. Then up another cup and so forth until you find that sweet spot. Also the little pigments and discoloration is nothing to be worried over. Looks like nature to me aka. Shit happens. Not big deal or even ANYTHING if that. Good luck dude! Also once the girls get to the edge if the cup its time to transplant. I see you toom care of that this week so you should be good!🤙