Hello I have a two new seedlings and I've been killing spider mites for the past 3 days. I used soapy water and silica with water and I'm killing them by hand, the bleed u can see it. I came home from work and saw two on one plant, they other none so I killed them. I'm wondering where there coming from because when I left I saw none. Are they coming from the dirt? How do I treat the soiI if so? I have some Asmax on the way.