Fog Dog maybe

It looks like the tips are a little burnt and some are twisted. A little bit dark yes it could be N tox but it could also be light burn. So a few things you can do to help, first always alter feeds with nutes and plain pH water, to avoid any issues such as N tox. But looking at it I think you may have used a little too much nutes pal, how the top of the plant appears to slightly twist a little can also be a sign of nute burn with the twisted leaf tips also. Give her some water for a couple of days and she'll be fine. With me thinking it could be the light also, just raise that and then that's you done all you can do.