a lil nute burn on one?
or is that from when they were getting hot?
have you checked the PH of your soil yet? i believe you can have it checked for little money at home depot, can also buy a cheap soil PH test kit for like 10 bucks. people say PH usually is not a issue with soil grows but i have been lurking these forums for a bit now and i see alot of issues with it, me and loyalty both had impropper PH levels, i just fixed mine he fixed his a while back and his plants definatly made a great comeback.
from what i understand nutrient burn starts in the verry tips and works its way to the middle where deficiencys start in the middle of the leaf node.
anyways, if you havent had the soil tested it really wouldnt hurt to get that done and raise/lower it if need be. ideal soil PH is 6.8