Virus or a deficiency? Affected only new plants I potted to the old mix

[stankar]

Guys,
I have recently posted a problem on a few of my plants on reddit which are having some kind of disease or a virus, maybe a deficiency, and I would like them to survive and recover if possible. There is no response so far, so I will try it over here.
Affected plants are new plants which I have potted to the old mix, the mix is the leftover mix from when I was trashing out the old plants last season, the plants had the same problem last year due to my deadly nutrient spray I have mistakenly mixed up.
The leaves are smaller, having a black spots which are at first visible from the bottom side of the leaves, and then visible on the top side which is looking like a necrosis. The overall grow is stunted, young leaves and shoots are drying out (dying).
I'm fertilizing once a week with a quater dose of Pepper and Tomato fertilizer NPK 7-4-6 or Biobizz Fishmix 5-1-4, adding a Worm tea, Calcium, Magnesium, Hesi Powerzyme, at the end lowering the Ph to around 5.8-6.2. I don't think it is overfertilized, but the previous mixed could have been.
There are definitely no pests.
You have probably seen it or expecienced it, do you know what it is and how to cure my plants?
Thanks

 

[solid7]

You don't need to feed a plant in soilless mix that often.  Espeically the calcium and magnesium - unless you can verify that you actually have a deficiency.
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It's really hard to say if there's anything really wrong with the plants, but the place to start, is to stop giving them so much attention.
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Young leaves and growth stunted could be overfertilizing, but the classic sign is leaf browning and drop.
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Is it possible that you could just limit your feeding to the fish fert, once every two weeks, and water the rest of the time?  At least for awhile?

 

[stankar]

It could be an overfertilizing, but I didn't see any typical signs... but yes, I have stopped fertilizing them 2 weeks ago, and will keep monitoring it. I should be able to have comparison with my re-potted plants which could recover faster.
WIll be back with an update in another week or two, so you can see if it is getting better or not.
Thanks so far