Young plants dying, help needed, pics included

So a friend of mine has his first grow going, the plants were doing okay the first days however later brown spots started appearing on the plant, he thought the problem was the bottled water (too many minerals) he was using, so he switched to distilled water, the plants looked okay at first, however later brown patches started appearing on the plants, later the leaves dried up, the potting soil was generic seedling soil

Looks like it's really really thirsty, but I wouldn't really know, I am interested because I haven't seen plants that looks like this before, so an answer would be nice.

This was just before watering, so they might look down

What kind of lights is he using bud? Is he using nutes?


EDIT: Take a look at the second post, might help;

https://www.rollitup.org/marijuana-plant-problems/762642-some-help-here-people.html

what kind of nute r u using on her looks pretty crispy. what kind of soil is that was there in it. bottled water and distilled water have a different ph. i would say that when he was using bottled water nute built up in soil and when the other water was used ph was right and all the nute got sucked up into plant "nute burn" i would flush with plane tap water and wait to see how bad it is and dont add nute till day 3 at 1/2 strength

Has your 'friend' thought about feeding it? its fucking starving and def in every nute known to man. The crappy cheap soil is the base of the problem.