I can't tell anything from the pictures. Others can infinitely better advise you about deficiencies and such. [I'd guess it's just the usual cal-mag deficiency].
But it would seem prudent to treat your plants as soon as possible at least with that herbal insecticide, since you even consider having a mite infestation, you haven't taken done any preventative treatments, and your spray is pretty harmless (and hopefully effective). Consider thoroughly spraying your plants. And add some cal-mag too, with thorough spraying including foliar feeding; and plants needing more cal-mag at that age is rather normal.
Here's what's at the Web site:
Akar-X Organic Acaricide insecticide
$5.00–$46.00 $3.00–$40.00
Aphids, spider mites, and other insects can cause serious damage to flowers, fruits, and vegetables. These creatures attack your garden in swarms, literally draining the life from your crops and often inviting disease in the process. Akar-X Organic Acaracide insecticide is based on the active ingredients Clove oil and Cinnamon oil. When combined with inert ingredients the essential oils in Akar-X Organic Acaracide insecticide become drastically more effective at killing the target insect species. Akar-X® is OMRI Listed®.
As plant essential oil-based insecticides go, this could be good stuff. But keep in mind, if you actually have mites, you are going to need to hit them harder, for real, and repeatedly. You might consider getting a pyrethrin product (if 'organic' enough for you) for potent quick killing (generally use only if needed) and/or a neem-based product which is more longer-acting. More of a long-term infestation preventative product, not potent at killing, also consider using SNS-209 (rosemary oil-based). I've recently been using just SNS-209 and Bt bacteria drops to kill any larvae in the medium (coco); and I'm not seeing any insects.
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lol..
