Ive had many problems with spider mites in the past powder mold, aphids, bud rot. I had the same worry as you, do I spray my precious babies with these chemicals, is it gonna hurt them? How long can I spray them for? I found Onyx spider mite spray, it keeps all the bugs away and stops pm from forming. Its all natural and organic, you can literally safely use it even after harvest, it doesnt burn or hurt the plants, it actually works great as a leaf shine also. I tend to spray throughout my entire harvest every other week or so, keeps the bugs and mites away.