Just FYI... over fertilisation of the medium causes a K deficiency. high slaintiy blocks the passage of K... ergo, high fertilisation = K deficiency.
that you clearly have. what concerns me is how you got there... is it over fertilisation or is it under fertilisation. That is the question....
Usually in an over fert situation the plant should be virtually free of red stems and the leaves should be a rich dark green. the only damage or discoloration we should see are the large fan leaves going necrotic from the edges of the leaves inwards. What concerns me with these pix are that I can see what appears to be plenty of red stems and the leaves are not as rich green as i'd expect. this is because nutrient formulas have pretty good amounts in them, fairly spread around. this makes over fert easier to spot.
what nutes do you use and how regular do you feed, etc?