I cant believe how long it took to get the rite answer, 4 fuckin pages haha
As a few said your problem by far is Nutrient lockout, in your pictures the biggest thing that came to minds right away way nitrogen Diffecency, it looks like other diffecencies as well but thats what I notice first, now since your nutes have proven good to you in the past and you are sure its a good mix, well that leads straight to salt build up and nute lock out.
Since you mentioned you reused your Hydroton I think this is your problem, I see this alot, if your growing hydro, dont be cheap, use new rocks for every grow, there are a number of problems tht stem from reusing rocks, even if your did get them good with Hydrogen peroxide.
its bin way to long, I need a bowl