What looks like is going on here with Curly? She's a freebie seed from Nirvana so I don't know the strain. This started about two weeks ago. Fed her and it got worse. Compared to the photos I found online and thought it might be Mg deficiency so got some Epsom salts, and tried that last week, it advanced dramatically this week! She is looking like one hurting unit. No other plants are bothered. In fact, I think the last feeding was a bit heavy as I see a little nute burn on the tips of two plants. Other than that everyone else looks great. I did just add a second 300w LED to my tent (looking to improve things for next grow). First grow, first everything. Made lots of mistakes, but have kept good notes and am learning a lot. This one came up relatively fast.