Spider mites are such a piece of cake compared to root aphids.

You really have a lot of treatment options as mentioned above, but the key is to act quickly and be diligent. Make sure to keep up regular treatments even after you think the mites are gone. Also, try to get your environment under control. Make it uncomfortable to spider mites by dropping temps, raising humidity, and making it windy.

FWIW, I found neem to be a very successfuly treatment in combination with pyrethrum, & soap or isopropyl solution. The NPS also completely eliminated them during flower, but they work best in a small room or tent....