Figuring out which element is causing the problem is a bitch. They all have symptoms in common with interveinal chlorosis in new growth happening with almost all of them. The most likely culprit from what those leaves look like is a manganese deficiency. "Telltale sign of Mn deficiency is where margins remain dark green surrounding interveinal chlorosis"
Problem is that they all kinda look like that.
The most common reason for deficiencies in micronutes is the pH being too high which makes them unavailable to the plants. Elements like Mn, Fe, Cu etc have to be in a slightly acidic state to be easily taken up by the plant. To get a truer reading of your runoff pH you need to water your plants enough that the soil is saturated. Remove any runoff that remains after a half hour or so and let the plants sit overnight. Then add a cup of water or so to force some more runoff and test that. It takes time for acid/base reactions to complete and testing what comes out when you first water is just showing you something close to the pH of the water you just added and not the true pH of the rootball your plants live in.
Just adjusting the pH of the water you feed your plants to what's good for them isn't enough to do much in a pot that has excess alkaline minerals in it. Kinda like putting a couple drops of vinegar in some baking soda. Sure it will fizz but there's still lots of baking soda left over. I see this a lot with people that use hard tap water. Every time they water excess minerals in the water get left behind. Like the scale in your kettle it builds up in the rootball and holds the pH above 7 no matter what you do. A real good flush will get a lot of it out but with a bunch of plants that's a real PITA. I avoid issues like that by only using RO water so the only minerals in that root ball are ones I added to the water at levels the plants can use up between feedings.
I don't know what kind of water you use but if it's tap water you should check the ppm or if you don't have a ppm pen then contact your water provider for a copy of their water analysis report. Should be free and they will likely email you one or they may post it on the town website. If they ask why you want a report tell them you want to brew beer or raise fish as if it's any of their f'n business eh.
To temporarily correct a high pH you can water them with pH 5 - 5.5 water and see if newer growth starts coming in greener. That takes a few days at least to notice and in the meantime the rootball has gone back to it's alkaline state and the elements are locked out again. How quickly that happens depends on the amount of minerals built up in the soil and there may be no noticeable improvement if the condition is severe.
You can buy trace elements at most garden centers you could add. They mostly come in granular form so best to grind them up fine and make sure to swirl the container around good just as you water or they will just sit on the bottom. About a tsp/20L as a little goes a long way and too much is as bad as too little. You won't see immediate improvement but if it is micronute deficiency things should get better soon. What would work better is to buy the Micro portion of any decent 3-part nutrient line. That will have all the elements in a chelated form easily used by the plants and should work better tho new growth will have to emerge to see if it's the fix. I use Advanced nutes with pH Perfect technology, ProMix soilless/soil blends and RO water and haven't checked my pH for a few years now.
I notice that you use silica. That stuff is very alkaline so should be added to the water first then the pH adjusted down to at least 7 before adding nutes. Put some on your skin and see how long it takes to itch and burn. Don't get it in your eyes or you'll be reading this in braille.
Here's a nice chart for figuring things out.
My garden as of ten minutes ago on day 27 of 12/12.
Good luck!
