How Do I Install an Undersink RO Membrane?

Before You Begin

Installing a reverse osmosis membrane is a straightforward process that takes just a few minutes when done correctly. Whether you are setting up a new system or replacing an existing membrane, proper installation ensures your RO system delivers the pure, clean water your family deserves.

Before starting, make sure you have the following ready:

Your new RO membrane
Clean towels or rags
A small container to catch any residual water

Opening the Membrane Housing

The membrane housing is the cylindrical container that holds your RO membrane. It is typically located horizontally within your countertop system and has a cap on one end.

Locating the Housing Cap

Identify the end cap of the membrane housing. This cap is usually secured by threading or a twist-lock mechanism.

Removing the Cap

Turn off the water supply to your RO system.
Relieve any pressure by opening the RO faucet until water stops flowing.
Place a towel beneath the housing to catch any water that may drip out.
Grip the housing cap firmly and turn it counterclockwise to unscrew it.
If the cap is tight, use a housing wrench for additional leverage.
Once loosened, remove the cap completely and set it aside.

Understanding Proper Membrane Orientation

Correct orientation is critical for your membrane to function properly. RO membranes are designed to allow water to flow in only one direction, so installing the membrane incorrectly will prevent your system from producing purified water.

Identifying the Stem End

Every RO membrane has two distinct ends:

Stem End: This end features a small protruding stem or tube, typically with two very small rubber rings. This is the end that connects to the system's internal fitting and is where the purified water exits the membrane.
Flat End: The opposite end is flat or has a larger opening. This is where feed water enters the membrane.

Important: The stem end must always be inserted first into the housing. Think of it as leading with the stem.

Inserting the Membrane Correctly

With the housing open and your membrane properly oriented, you are ready for installation.

Installation Steps

Remove the new membrane from its packaging. If you are replacing an old membrane, pull the existing one out first by gripping and pulling firmly.
Inspect the O-rings on the membrane to ensure they are intact and properly seated.
Hold the membrane with the stem end facing the inside of the housing.
Gently push the membrane into the housing, stem end first.
Continue pushing until you feel the stem seat firmly into the internal fitting. You may feel a slight resistance as the O-rings create a seal.
Ensure the membrane is fully inserted and seated securely.

Tips for Smooth Insertion

If the membrane does not slide in easily, apply a small amount of food-grade silicone lubricant to the O-rings.
Never force the membrane. If it does not fit, verify you have the correct replacement membrane for your system model.
Make sure the membrane is straight and aligned with the housing to avoid damage to the O-rings.

Securing the Housing Cap

Once the membrane is properly installed, it is time to seal the housing.

Inspect the housing cap O-ring for any damage or debris. Clean or replace if necessary.
Apply a thin layer of food-grade silicone lubricant to the cap O-ring for a better seal.
Align the cap with the housing threads.
Turn the cap clockwise to begin threading it onto the housing.
Hand-tighten the cap until it is snug. Avoid over-tightening, which can damage the threads or O-ring.
If using a housing wrench, apply only gentle additional pressure to ensure a watertight seal.

Post-Installation Flushing

After installing a new RO membrane, flushing the system is essential to remove any preservatives and carbon fines, ensuring your water is clean and tastes great from the first glass.

Flushing Procedure

Turn the water supply back on to your RO system.
Check the housing cap and all connections for leaks. Tighten slightly if needed.
Allow the storage tank to fill completely. This may take 1 to 2 hours depending on your water pressure.
Once the tank is full, open the RO faucet and drain the entire tank.
Repeat this fill-and-drain cycle at least two more times for a total of three full tank flushes.
After the third flush, your system is ready for regular use.

Why Flushing Matters

New RO membranes are shipped with a preservative solution that keeps them moist during storage. Flushing removes this preservative along with any loose carbon particles from new filters. Skipping this step may result in an off-taste in your water for the first few days of use.

Need Additional Help?

If you encounter any issues during installation or have questions about your specific Crystal Quest system, our customer support team is here to help. We are committed to ensuring you enjoy the cleanest, purest water possible.

Contact us through our website or give us a call, and one of our water treatment specialists will be happy to assist you.