Would need more info.
Alright so I’ve been having the light on 24/7 I’ve get told you could do that and some said it’s not good for them which that’s probably the case and I do have a fan that’s goes on at 6pm-6am and I water them like every 2 days
Looks like nute burn?
What do I do? would it be my lights because I do have them on for awhile I’m meaning to change it to 12/12
possibly light burn , how far away is the light ?
Take pics in regular light, hard to tell in that light but may be a pH issue.
Also what are you growing in, nutes and amounts
I sent a picture
By chance what is the temp and humidity in the grow tent/room, can you check leaf temp under the lights?
I deal with such a variety of plants sometimes these issues stump me a bit. If that was a tomato I'd say you overwatered and temps to high. The top of that plant to me look like heat issue also a possible pH issue looking at lower leaves.
Are you in soil or coco coir?
How old is the plant?
What is the PPM of the runoff?
What is the temperature in the grow environment?
What is the humidity in the grow environment?
What light are you using it and how far away is it from the top of the plant?