Can just a fan keep spider mites from being born?????

To be totally honest I have No idea what these little bugs are! White little fast runners.!
How can I avoid getting spider Mites? Where in the Heck do these little suckers come from, the soil? Was there something done wrong during the plants grow to cause spider mites? Why do some Mary Jane plants get spider Mites and some Plants don't?
I'm asking this because I think I saw a little baster running on the inner side of flower Pot!
Now I have to go out and Buy something to control this before I have an infestation!
I was doing some research and found something called "Liquid Lady Bug" I'm wondering If i should go out and purchase some, the only thing that bothers me its about $30, wow that's alot!
Please someone help me! I need some great advice because this is my first grow and I don't want the buggers to make me unhappy!

CAN SOMETHING AS SIMPLE AS A FAN KEEP SPIDER MITES AWAY? IS IT THE MOISTURE OR SOIL THAT BRINGS THESE SUCKERS TO LIFE??????????

you wont notice one mite, they are very very tinny. the leaves will start to show small yellow spots long before you notice the bugs. get a strong magnifing glass and check the underside of the leaves, if the tops show spots. mine do. =end all spray.

Yeah, that little running thing was not a mite, they are so small you would never notice em running, besides they crawl, look like tiny tiny ticks! Mites come from outside, or plants that are already infested yet have gone unnoticed like donor clones. They are not soil born they are air born, they ride wind currents to move from plant to plant, or crawl if another plant is directly adjacent. It just happens has nothing to do with moisture, although they love dry atmosphere, and are slowed down by high humidity or rain,(simulate this by spraying your plants, especially the undersides which is where they primarily reside). Never heard of liq. ladybugs, but I do know that real ladybugs are only 10$ for a few hundred and can control pest populations that are NOT at a critical level. But they only eat slow moving bugs like mites and aphids, if you saw a bug "running" then the lady bugs wont stop them, I use lady bugs only when plants are deep into flowering and I dont want to use any chemicals, organic or otherwise, because I dont want to ruin the taste or scent of the flowers, plus ladybugs are a 24/7 army of carnivores that comb over every surface of a plant looking for food, and do a better job than most humans would. If your plants are just vegging, use Doktor Doom spray, 15$ and it kills on contact while having very little damage to the foliage, just spray the underside of all leaves and dont breath that shit it!!!

Oh and no, a fan will just blow more mites around your room spreading them out, but then again, I'm not sure you have mites, get a dope scope, get a good look at the pest, then compare it to a google image and tell us for sure what it is, then we could better diagnose your situation!