The Pentair GRO50-RC (655121-96, 12 Pack; 4005742, 1 Pack) is the reverse osmosis membrane replacement for the Pentair FreshPoint GRO-350B Reverse Osmosis System. It is a high-efficiency 50 GPD membrane and should be replaced every 12–18 months, or sooner if TDS testing shows reduced performance.
Step-by-Step Replacement Guide
- Turn off the water supply to the system and open the faucet until water flow stops, then wait 5–10 minutes for the RO membrane to fully depressurize. Place a bucket or towel under the system to catch any drips.
- Lift the locking bar upward until the membrane cartridge disengages from the filter head assembly.
- Pull the membrane cartridge away from the filter head assembly, and make sure the locking bar stays fully in the up position.
- Align the posts on the new GRO50-RC membrane with the ports on the filter head assembly, then slide the cartridge into place. This engages the locking bar, causing it to drop forward and down.
- Pull the locking bar down until it snaps securely into place.
- Turn the water supply back on and check all fittings for leaks. Close the storage tank valve and let the faucet drip for 30 minutes, then fully open the water supply and let the faucet drip for a few more hours to flush the new membrane before closing the faucet and opening the tank valve to refill.
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