First Photo Grow - OPERATION: FILL A 5X5

Yes you are correct. Leaves won't repair themselves, but symptoms should stop. Good diagnosis and immediate fix. 👍🌱

Looks like nute burn to me. If they aren't getting enough water, then they cant absorb the nutes and get nute burn (even if you are feeding low on the nutes). They don't look thirsty, but that could be the timing of your photos. 1/4 gal (~1L) a day for a pot of that size doesn't seem like much water to me. I was watering my plants in 20L pots 5L of water every 2-3 days. Why don't you try watering them up until you see run off for the next few waterings. Lift the pot up and take a mental note of how heavy the weight feels. Give it a couple of days and then lift the pot again and see how much lighter it feels. If it feels lighter, repeat the process. Watering to run off allows you to confirm that the plant has enough water and unless you water again too soon, it won't overwater the plants. I was underwatering mine dramatically with my first grow and I really paid the price. I also use this great deficiency guide when I run into problems: https://dutch-passion.com/en/blog/a-visual-guide-to-cannabis-deficiencies-n987. Your plants probably match the potassium deficiency the best as the burn is on the side of the leaves and not always at the ends. Check your NPK breakdown and up the potassium if you think its a little low. I would suggest you try the watering idea either way. Good luck!