Pull off the dead/damaged growth and flush the shit out of it. Looks crispy to me. I say pull it off so you have a better understanding of whether or not the problem continues after you implement some solutions. Leave them on if you want (no pun intended), but it's just a leaf. I prune and LST like a mofo and as long as you know what the fuck you're doing, pruning is a good thing.
I use MG (actually Expert Gardener 10-15-10 from Wal-Mart) and get amazing results. Sunshine (Sun-Gro 810) soil. It's a fairly weak soil from the get-go. Much like FFOF but better and CHEAPER. Anyway, flush and then hit them with some 1/4 strength MG (little scoop side) EVERY watering. Also, even though I use tap, I supplement with Cal-Mag. My tap comes from a river that has an EXTREMELY low calcium count. Don't ever beileve that you don't need Cal-Mag with your tap. Look up an analysis and make your own decision.
I vote for crispy. Flush and when they're dry, hit 'em with 1/4 strength nutes and 5ml of Cal-Mag per gallon EVERY watering. Never had a problem since doing this.
Don't ever forget that these are WEED plants NOT orchids or some ornamental shit. Keep it simple. IT'S A WEED.
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