Ask on RIU and you'll get 100 different answers and 90 of them will be WRONG or ineffective. There are tons of products and most work to some degree, but not enough to wipe out them out for good. Stay in veg until the problem is solved, do not start flowering as most of the products will damage or kill you buds AND you don't want to smoke chemicals, etc.
So, how to proceed?????? The key is to identify the type of mite you actually have. Most products DO NOT WORK on all types of mites. Get a good magnifyer and try to identify the insect. There are Russet mites, Broad mites, etc., etc.- many different kinds to be sure. Some are tougher to get rid of than others.
For me, I've tried everything on the market at one time or another. I found the best thing for my type of mites was Forbid 4F, bought on Ebay for $20- a small container of it. It has a 45 days residual effect to kills mites longer and travels from the top of leaves to underneath to become more effective. If you spray it well, you won't have to spray again. Do it in the dark period and let it dry overnight with no fans on so it's not blown off the leaves. It will kills eggs, mites, etc.