Deep Purple growing nicely! Have a pruning/fert question.

So my question is; im cutting a few fan leaves off tonight is it cool if i water them with some "fox farm grow big" after I prune?

Don't cut off healthy fan leaves. Fertilizers have instructions on how to use them on the label....No offence but if you are not sure about how to use simple fertilizers then you should head over to the Newbie section, you will surely get more help and learn more there.