The tell-tale sign for most mites is the white dots on the leaves from the mites sucking the chlorophyll juice from underneath.....and of course the mites and eggs underneath too.
Hey Grease....your issue looks more like a Cal/mag issue from the taco-ing of the leaves or over heating from the lamps.
That wasn't my pics man, that was the internet's, under russets.
And that's exactly what it looks like, hopefully you'll never need to deal with them.
I didn't take pics of mine, had bigger things to deal with.. should have though
But it basicly ALL growing tips would shrivle up and turn a weirdish yellow, almost like a sever nitrogen def, or if the plants had three days of darkness (don't ask how I know what that looks like) it tacos up from the plants losing all it's water/juices..
trust me, the infestation I had was monumental.
And you cannot see a damn thing with a naked eye, these things are WAY smaller than reg mites.
But NOTHING compared to these radioactive spider mites that are here in the redwoods.
Believe me, these spider mites are insane, they live through everything.
the russets I had under control in about two weeks, and it was cake compared to these fuckin spider mites.
Maybe I was lucky, but they didn't spread nearly as fast as the reg mites, and didn't come back, I've had 6 runs since, no problems (knock on wood)