if nutrients were just overall low, not any one specific mineral, just the overall entire feed is low, the entire plant would go paler green and bottom leaves would start yellowing and dieing off as it uses those leaves to feed its hunger sacrificing them to live on.
All nutrients are salts. Salts are acidic. This drives the medium pH down. High level of functioning organics and life in the soil, combined with ph buffering substances like Dolomite Lime, which is added to promix for an initial charge for initial plant growth keeps the pH in check no matter what the pH of your source water is, but salts impede microbe function, and Dol.Lime only lasts so long, and your plants are big.. acid is constantly being neutralized using up the dolomite lime power to correct pH back up to soil range until there is no more pH buffering dolomite lime effect and soil takes on it's natural peat base pH, which is very acidic by the way. You get weird deficiencies, burns, twisted/curled leaves. This is not the plant in need of something, it's the plant being unable to feed on what is there at it's feet, and what is there is all interacting and acting as salts without any plant uptake, and then more nutrients are added, compounding the problem. Antagonistic, not deficient.
So which do you think you have, considering you feed 4-5 times nutrients in a row, and are starting to get weird spots/burns showing some kind of deficiency, but how a deficiency? you feed feed feed feed feed? Are the plant's just THAT hungry.. then feed them.. but if you're wrong.. u-oH for all the reasons stated above.
What I suggested stands, just explaining my brain process. I could be wrong, after all, I'm just going by some pics of some very healthy super duper plants.. adding more is no big deal as time goes on.. taking away is PITA..