JBL Proflora Complete System KitA complete CO2 and plant fertiliser system kit with refillable 500g cylinder and night switch off, including accessories available in 3 models for different aquarium volumes. Key Features: CO2 fertiliser system for the best feeding of fast and slow growing plants in freshwater aquariums. Assemble system, attach diffuser in the aquarium and adjust CO2 supply until the permanent test indicates the ideal value. Professional water care with night switch