The plant is under atack, this will trigger MATI(Mites Atack Triggered Imunity), wich will make the plant stronger, if its just a couple spiders worry not, kill some with your hands if you wish and leave others that you can't see, if they are a huge pest then kill em all, KILL EM ALL WITH FIRE!!! No, just kiding, don't kill them with fire, use neem oil, or let a clove of garlic sit in water for 24h and use that water to spray the leaves.
If you can kill majority manually and leave some, that also lets the plant develop MATI wich will be benefitial.
Good luck growmie and stay lit.