30 meters need 16 mm (blue) 16 mm should be used for larger systems - usually all systems with six or more pots (1Pot XL / XL SmartPot) and all systems with eight or more pots (1Pot / easy2grow). Use together with 16mm-9mm or 16-6mm fittings to reduce the need for bonding to AQUAvalves blue 16 mm is required 30 meters
