Hello 303, I have been growing for 1/2 a year now.
About 2 1/2 months into my first veg I noticed I had spidermites on all of my plants. Now it wasn't a very large infestation (the mites would sometimes go up mid plant, but their numbers were sparse here) I mostly had a problem with the bottom 6 inches of the plants. I started mixing a 1/2 quart spray bottle with water and a drop of dish soap (I used Dawn)
I would take every plant to my desk, prop it up and put a light underneath the plant so I could inspect from above and below and get a better understanding as to where they were really accumulating and reproducing. I would begin by removing (if I thought the plant could do without) the leaves which were really infected at the highest point in first and making my way down to the bottom. I would then take my spray bottle (moving every fan I had as far away and misdirecting the wind) and spray rather vigorously in every spot I noticed eggs and mites, hoping to knock them down and in sense drown them out. I continued to do this to every plant for 3 days.
After this I noticed a very nice change, they were definitely still there; but my effort was proving fruitful. I moved my plants in a rotation away from my fans that would promote the best air flow for the bugs (if they went airborne) to land on my most affected plant. I waited a day for results, sure enough, my most infested plant was still the worse, I even noticed that 2 of the plants closest to the fan were clean.
Now I really wanted them gone, I bought something called "Einstein Oil" I'm not exactly sure who makes it but it is a first pressed, cold neem oil. It's a little less "sludgey" than other neem oils. I bought mine for 20 bucks for a pretty small container, but it goes along way. Anyway! What I did was I filled another 1/2 quart spray bottle with a 90 degree nozzle, and added a teaspoon of the einstein oil and a drop or two of dawn liquid soap. I then proceeded to spray each and every plant once a day for 4 days straight. By day 5 I had ZERO spidermites. I caught them quick though.
Just my story. Good Luck dude
-d'Artagnan