General Hydroponics® RapidStart® 1-0.5-1 - 1LGeneral Hydroponics RapidStart 1 0. 5 1 1L RapidStart is a plant nutrient used to promote root growth while enhancing plant vigor and yield. Strong root networks are linked to larger, more vigorous plants. RapidStart helps plants develop strong root networks. It can be used throughout the vegetative growth stage and in early flower stage to continue to promote root development. Guaranteed Analysis: Total Nitrogen (N) 1. 0%, Available Phosphate (PO) 0.