Spider mites hate water and cold. Spray the top of your soil with the standard Neem + Potassic Soap, try diatomaceus earths and yellow sticky traps, and also make sure soil gets cold, rainy weather if possible (winter is perfect to stop them).
But you must know they leave lots of eggs, and a sudden hot day might make them come back, you need to quarantine your soil, make sure you don't move infested plants with healthy plants or clones.
It's a lot of work but it's possible to definitely erradicate them and to keep them at track too.
Keep on the great care!
Happy smokes!