dying cannabis plant

Hi, new to all this so excuse me if i've got something wrong or posted it in the wrong place! Need a hand here, my seedlings seem to have white patches over them and bottom set of leaves are drying and dying!! Have attached pics. Thanks!!!:???::???:

HELP! I have a plant that was about 1-2 weeks from harvest. I think I added too much nutes or perhaps too much light, either way all fan leaves turned brown and dried and died, the sugar leaves are now drying and dying. I've reduced light to 10/14 to try and speed the ripening of trichs. Can...