Canna PK 13/14. Should you cut back on nutes?

I was curious if you have a full Canna grow should you cut back all your Nutes when adding your PK 13/14? I've also read that depending on your flower time this would depend on which week to start adding but what if you started adding PK 13/14 in a really super small amount as soon as you see pistils if it would be good or bad or just a waste of time? Thanks in advance.