what do red spider mites hate

It might depend on where you live in the world, however I've always been quite lucky with the old shower trick. Literally showering the entire plant. Followed up by daily misting. If you don't want to use chemicals it might be worth purchasing the predatory mite Phytosieulus persimilis. Don't bother unless the temperature is above 18°C (64°F) though

I agree, keep the humidity high and they will not be a problem.