Two conditions the little bastards like: hot and dry. Misting the plants might help, or you can try lowering the temperature a few degrees, which is supposed to slow down their feeding and breeding. Some say oils like neem will do the trick, others claim they've tried oils that didn't work. Aside from predator mites, another organic method is spinosad, which you can get in Capt. Jack's Dead Bug spray. Oh, another thing, if you have a CO2 system, you can hike up the CO2 concentration in the air until it suffocates the mites and it won't hurt the plants, or so I'm told.