a picture would be a major help bro. I can think of about 12 things possibly wrong (if not more) but I dont want to stear you wrong
this would help anyone here to cure your ills......How to Ask for Grow Support
Im going to go out on limb Buzo. check your PH. what was your Ph on the runoff of your last watering? are you even checking for it? alot of people dont so if you arent do be upset.
look at the second pic Do The Leaves have Burnt Blotches on Them?
it looks like the beginning of this damage IMO