What are you growing in ? soil... it can be your ph...wind burn..heat...light to close.. without more info it's hard to tell. Is it in flower? Different lights? Any and all info will help
Hey, bro. It's ok. You can fix it. The pH level of your soil is bad. Are you sure you are not overwatering it? I bet the humidity is too low. See how the ends curl down? Check your pH and increase the humidity to 60-70.