could be PH as well from the browning...whats the ph in the containers? needs to be 6.5 test runoff when u water and youll see about where the roots are lookin like. *also a flush wouldnt be a bad idea to help rid the extra nutrients and to PH the containers.
yup, now that i gave it another view and enlarged the pic, it deffinately is nuteburn. the browning on the edge says so. might be a ph prob if you look tward the lower portions of shade leaves, if it was just a yellowing like it looks w/o the pic enlarged i would say hungry but shuggy called this one about the burn.
I agree with the fine gentlemen above me...nute burn. It was a N def, you have a more gradual yellow among the bottom leaves and most likely not any browning... a good flush is in store and cut back on nutes and/or percentage of them...