Is there something about the plants leaves or roots...looks wise...that makes you think they are hurting the plant??? Do they move around?? Are they quick or slow (good rule of thumb on mites..quick moving= good mite, slow moving=bad mite)??? Do they hide fropm light??

I'm not sure if they are hurting them or not--most seem ok and I didn't see any marks on the roots that seemed like damage (but I'm no expert). Some of my plants aren't doing as well as I'd expect, and I don't want to be sitting by while they undergo a slow death. I'm not sure what I would call their speed of movement--I don't have much to compare it to. I suppose more on the slow side. I'm pretty sure I have (or had) two different kinds as well. One slightly larger and more silvery and the other smaller and more beige colored. . . I would say that they do hide from light. Thanks!

If I were you, I think that I would find some food/horticultural grade diatomaceous earth (found in garden centers) and sprinkle it liberally on the soil. It will work physically to reduce the number of these uninvited critters. DE is not a chemical toxin but take care when applying it so that you don't inhale the dust.

(Funny, you could EAT it but you just don't want it in your lungs.)

ara80,

There will always be "exceptions", "but..." for a plant/insect situation.
With that said, I personally don't think you have a problem. Most mite "pests" cause problems above the soil line, not below!!!
If it is just the thought of them being there that worries you, the DE mentioned above is a good idea...it is what I use in my home for fungus gnat larvae, works like a charm. It would take it a bit to work its way thru the root mass, so I personally question if it would work well on these "critters"...but a sound means of controlling some root pests.
Another means..."much" more labor & cost intensive...submerge the root zone in 120'F water(NO HIGHER)for about 5 or so minutes....works wonders on root pests.

I did buy some DE but haven't had a chance to use it yet. Should I try to work in into the soil any or water more to help get it further into the soil? Schmoo--I do so hope you're right! Hopefully they're not really a problem. I do also have fungus gnats and will be very happy if the DE gets ride of them! I also surprisingly had a plant with mealybugs that I noticed the other night--I threw it away. Do they spread easily. . .? Thanks!!

Diamotaceous Earth works as an insecticide because the sharp edges on the particles pierce the insects body. Once the DE is wet it looses all insecticidal properties, so DE should only be sprinkled onto the soil surface and replenished when it is wet. The easiest means of control of Fungus Gnats is to not water the plants quite as much and place Yellow Sticky traps to catch the adults. A plant with mealy bugs need not be tossed out because control is fairly easy with regular showers and maybe some insecticidal soap sprays.

ara80,

No need to work the DE in...I have always tried to apply over entire container surface, lightly water (that allows it it work its way down a little), then stop watering for as long as feasible (the larvae hang out close to the surface, so you are getting the DE into the "zone of hanging out"). I personally have never had to reapply once this was done, has worked for me every time. While I agree the DE is not effective when wet, once dry, it is back in good form (DE is 80-90%+ silica....water is not going to break it down)

Schmoo

Exactly, Schmoo! DE is even effective when made into a slurry so that it can be watered in more thoroughly. Once the particles enter the pore spaces, they pose some real problems for soil borne critters!

"...zone of hanging out..." Good one! :-)