Pest

I would say you have pests in your grow and you should spray with preventative measures or insecticide, preferably eco-friendly, like neem oil, pyrethrins, or something similar. Cheers, my friend, and good luck!! 👋😎👍 🍀🍀🍀

look like trhips => spinosad work real well agaisnt them

@Ezzjaybruh you're right, it's a bit different because you don't see any black spots, which would be poop :D the control is quite simple, meaning humidity is key unless you're in flowering, neem oil sprayed on the leaves but complete elimination takes a bit longer, you can also use blue sticky traps that work better with thrips anyway, you'll find other methods online... remember to disinfect everything after the cycle...

My best guess is thrips.. looks a bit different than normal but if the damage is that bad you should be able to find some if you have a good eye. Usually yellow REALLY small little biggers long body