The CANNA additives are products that can be used alongside the base fertilizers. Additives improve plant health and yield. They are not essential for your growth, as everything is in the base fertilizer. But the additives will give your plants the little extra for optimal growth and flowering. The CANNA additive range includes RHIZOTONIC XP, CANNAZYM, CANNABOOST, CANNA PK 13/14 and CANNA START.