Use the HydroLogic Reverse Osmosis (RO) Water Filter ¼" OD (outer diameter) Black or Blue Tubing for micRO-75™, Stealth-RO™, or smallBoy® to customize your indoor hydroponic garden. Use the HydroLogic Reverse Osmosis (RO) Water Filter ⅜" OD (outer diameter) Black or Blue Tubing for Evolution-RO™ or Merlin-Garden Pro™ to customize your indoor hydroponic garden.
