Sure, I use dyna grow foliage pro and it's 9-3-6, just mite see it is over kill and you'll half to delete it but I'd say go ahead and try but do it carefully
seems kinda high like a hardener. i would start off really light. like 1/8 to 1/4 strength. it really depends on how sensitive your strain is. if it's a strong sativa dominant i would hardly give it any.