if you just amped up p or k concentration, i'd consider that as the cause. despite popular belief, jolting the ppms of p or k above what the plant can use causes more problems than any perceived benefit. i see thin blades on new growth and some chlorosis there too.. along with tip burn.. all 3 are signs of p or k tox. i don't know what all these branded prodcuts mean, but the ubiquitous ingredients used in them are no different than any other fertilizer, give or take.