From what I understand (from diggin around the forums) spider mites are pretty common when growing indoors.I'm not sure if most experienced growers use a preventitive regularly but after dealing with them on my first grow I will be using the neem oil (its organic) for awhile and see how it goes.I used Azamax when I got em...sprayed,drenched the soil the next day w/it and then sprayed again 4 days after the first spray to get the unhatched eggs.Its been 5-6 days and I havent seen any sign of em.