I use habenero pepper water for spidermites.
Its harsh, wear a mask and gloves and glasses...
Just find red habs and mince them and the seeds, the seeds are super spicy. Then take one gallon and but about 10-15 minced habs in the water and add some fresh minced garlic for added effect, you can also add a strong mint like pepper mint or spearmint. You can add cloves and rosemary and teatree oil.
Look up plants that repel insects and go find them, mince them, add to water, let sit for 24-72 hrs, strain into a spray bottle and spray, coat the surfaces of the leaves very well, you can add a bit of soap to help it stick. Dont forget to respray a few days later and then make a routine of it throughout the grow.
I personally like neem, its easy and works great!
Good luck