they work great as long as you have a proper enviroment for them to thrive in ... Humidity kept @ min 60 % R.H all the time .. this helps them to reproduce thus helping control your mite problem. Try and spray them down with Einstien/Neem with some penetrator as much as you can during veg ... If you do it once a week for @ least 3 weeks your pest/disease problems will cease. ( I use a commercial paint sprayer and it works AWESOME !!! I gotta bad back so the ol spray bottle just dont do it lol)