if you are starting over w/ a new grow spray a diluted solution of bleach/water in the room and surrounding area before putting new plants in. also neem oil is best for spidermites you gotta spray generously on plants especially under leaves and repeat every 5 days mine went away after 4 cycles of spraying there has'nt been any since. be sure to keep the area clean, and from time to time take all plants out of the room and spray with the bleach solution to prevent them from colonizing in the future. if you get lazy they will get in