No matter how clean your facility is you are still susceptible to infestation. Most cultivators believe that by starilizing the environment around them they have circumvented the need to treat for pests.  Trust me guys if you get a room at the Ritz it don’t mean you can skip the profilactics with the girl you just met at the bar!  The disease is on the plants not the room! Focus on treating the plants themselves.  consistency is key.
You can use the elements to your advantage and battle pests passively. The most effective defense agianst pests is simply moving faster than they do.  Make your plants grow faster than the pests reproductive cycle. Most infestations occur at 3 months.
When shopping for soil choose one with a wetting agent. that will distribute and control water more effectively avoiding “wet feet”. Most organic soils distribute water porely and invite pests.  When shopping for nutrients choose “clean” ones.  You won’t attract large animals like bears nor will you attract contagious plagues like fungus gnats, thrips or root aphids.
When planting keep your beds or pots “shallow”.  The larger surface area to soil volume ratio will allow you to control moisture and in turn control of pests.  Do not overwater. Most cultivators are overwatering today.
If you are growing clones, try to find what you are growing in seed stock.  start your moms from seed once a year then propogate your clones.  You will start each year from a clean slate. At least you won’t still be fighting last years mites!
Understand how to manipulate temperature and humidity.  Spider mites hate cool humid conditions.  PM hates hot arid conditions.  Simply create the appropriate conditions to mitigate your current threat.
The proliferation of the spider mite today, is perpetuated by human nature. Most cultivators make the same mistake.  While their plant canopy is “filling in”, they allow the soil surface to dry out on a daily basis.  This dry surface when hit by the sun bounces arid heat back at the plants, dehydrating and emaciating the leaves.  This “frying pan effect”, drains the plants during early growth leaving them vulnerable to pests. By simply keeping the soil surface continually (visibly) moist you will reverse this process, turning a negative into a positive.  When the sun hits the wet surface it radiates humidity at the underside of the leaves pumping them full of moisture, making the plant vertually impervious to infestations.
In any event you are going to cover all of your bases and subscribe to a rigorous treatment program.  Today kangen PH adjustable water replaces all pesticides.  “Dip” or “Humidify” your plants in 11.5 PH water and say goodbye to PM.  Dip or humidify your plants in 2.5 PH water and say goodbye to spider mites.
When it comes to soil based pests put neem seed meal in your soil mix and use nematodes religiously.
Don’t bother spraying, it doesn’t work.  Submerge your plants upside down in whatever you are using.  While you are in a contained area (veg. room or greenhouse) “Dip” your plants during every up-potting procedure.  By the time you get them into the field the pests will be long gone……..These passive strategies allow you to manipulate your eniviroment to mitigate your pest problems without ever purchasing harmfull poisons!