This is in a 3'×5'×7' orchid tent.
2,000 predatory mites in such a small space is much higher than recommended release rates. I've had very good luck with these, with pest mites undetectable for months.
Another batch will be introduced about a month from now.
True, not every single pest mite will be eaten.
But many will, hopefully enough to remain undetectable until next year, at the very least.