I had mite once last year. I had to restart 4 plants which I waited 3 weeks or more to treat them. There was 1 plant that recovered without restart because I treated it within a week. Hope this help.

See irina comments on 11/14 to me. She said the plant will grow out of mite damage.

http://forums.gardenweb.com/discussions/4279203/feels-like-i-have-mites-plus-pics-under-magnification

I had mites after the trip to the last AV Convention., I had 2 trays affected, treated the whole stand, and the affected plants 2 more times

Gone. .The only issue I have = next time - I will treat the undamaged plants - and take leaves off the damaged to put down - It takes way too long to grow our of the mite damage. i will be better starting them from scratch.

Seems that if you refresh your collection every so often - and replace some of the plants wih the new ones - sooner or later you get them. With all the precautions - you just take care of the problem ASAP and in a decisive manner.