I remember one grow where my crop became infested with spidermites. They was about a week into flower, and around 40% of the leaves where covered in yellow spots where the mites had been sucking the life out of them. On closer inspection at the bottom of the leaves, just at the node sections there was really fine webs, and this was every where!
All this happened in only a matter of 1 week, as I left someone to look after things while I was away. Problem is, they never knew the signs and it got bad. Quick, real quick!
I panicked, and thought this was game over. I read articles and scoured every cannabis forum on the internet.
One product jumped out at me straight away. It had nothing but good reviews.
The only negative feedback I found was that it never displayed the ingredients, and the company who made the stuff had the ingredients close to their chest. This is understandable, but at the same time you don't know what nasty chemicals it contains.
Anyway, I bought some and followed the instructions. After 3 - 4 days, I noticed that things wasn't getting any worse, so this was a good sign. After a week, things still wasn't getting any worse, but they still hadn't packed up and left yet!
Then I found a product called phytoseiulus - they are a natural predatory spider mite and will feed of the spider mites in your grow room.
I stopped using plant vitality and order these mites. They came in a little plastic test tube. On the packet it said to just open the lid and leave the tube in the grow room. They will then go off in search of feed and lay eggs.
And that's what they Did. They went off and a had a feast. Within a couple of days they had gone! I couldn't believe it! No webs, no spidermites, nothing. Job done.
So that's what I'd recommend to you. I'm sure you'll see your ladies through to harvest in prime condition.
Good luck!