I would say NO, it is not. Here is a link, ( did not read it ) but the picture within has good examples of what i know to be magnesium def. Epsom Salts - UK420 ~~~~~~~~~~~~~~~~ I do not know what it is, Possibly scorching from spaying under high light/ temerature situations. Im sure someone here has had that exact problem. However, Your plants look fairly far along to me. Are they? dont forget that a good long leach is vital for nice clean smooth smoke, Organic ninjas please ingore this statement.