Weird leaf problem?

Is this a leaf that had been showing signs of deficiency before? Is this new growth? If it is an old leaf, I wouldn't worry about it as you really can't expect an old damaged leaf to repair itself. If it is a new leaf, you have a new problem... and it might have to do with root rot. This is not your typical deficiency showing up here! Are you letting your plant dry out completely before giving it more water/feed? One thing I've seen in your diary is that you're growing in plastic or ceramic pots... this doesn't allow the roots any oxygen (I am going to hope here they at least have holes for drainage) ... Since it's a photo, you might want to consider getting it out of that pot and getting it into a fabric pot... and yeah, I wouldn't switch up growing mediums in the middle of a grow again... but I'm sure you've figured that out yourself! If you re-pot into a fabric pot, you might consider re-vegging and giving her a little breathing space to adapt.... Good luck!