Replace your old RO membrane with this D&D Replacement RO 75 Membrane, keeping your reverse osmosis unit kicking out plenty of clean and clear, aquarium friendly water.
The membrane is designed to take the very last particles and pollutants from the water, leaving perfectly pure water each time.
It will fit any RO unit of the same specifications too, so it's very versatile. Simply discard the old membrane and replace with the new model.
D&D recommend changing the delicate membrane every two years. Although it may need replacing sooner depending upon the water quality in your location.
Note that a matching flow restrictor must be used on the waste pipe specific to the membrane output.