Is this all caused by spider mites?

It seems about 1/4 of my plants in flower have very yellow leaves, I have checked the pH with a test prod and those vial colour checking kits, both read in-between 6 and 7. I have given them regular flushings with straight water, I also tried reducing nutrients and changing brands of food. I don't think there's any issues with the water but I might be wrong, the one real issue in my room is spider mites, is it possible that most of the damage on the leaf in the attachment is caused by the mite issue? I think there's a little nute burn on the edges, but I would like an experts opinion. The yields on the plants in question is also about 50% lower than the healthy plants.

Any help would be appreciated.

The breed in question is NL from Nirvana Shop.