Hi
@Love2Bud! Canna has a very nice tool to help you determine your perfect feeding schedule: http://www.canna-uk.com/growguide. Since you're growing an autoflowering strain, I recommend to follow their "light feeding" schedule. According to this schedule, PK13/14 should be added during middle flowering, when the stretch is over, preflowers have appeared everywhere and started to develop. PK13/14 will help those bud sites to expand and become beautiful flowers, but it should be used with caution, only during middle flowering and during 7~10 days, no more. Hope this will help, keep us updated and happy growing! 👊