RO Membrane Installation & Replacement Guide
Time
15–30 minutes
Difficulty
DIY Friendly
Tools & Materials Required
- Membrane housing wrench (supplied with most RO systems)
- Clean bucket or towels
- Clean hands / disposable gloves (recommended)
Installation Steps
- 1
Turn Off Water Supply
Locate and close the feed water valve to your RO system. This is usually a valve on the cold water supply line under your sink.
Never skip this step — attempting to open the membrane housing with water pressure can cause flooding.
- 2
Depressurize the System
Open the RO tap/faucet and let all water drain from the system. This removes pressure from the system before you open it.
- 3
Locate the Membrane Housing
The membrane housing is usually the largest of the filter housings — often a vertical cylinder. Check your RO system manual if unsure.
- 4
Remove the Membrane Housing Cap
Using the membrane housing wrench, turn the housing cap counter-clockwise to loosen and remove it. Have your bucket ready.
- 5
Remove the Old Membrane
Pull the old membrane straight out from the housing. It may require gentle but firm pulling. Note the orientation (brine seal end first, or check your system manual).
- 6
Flush the New Membrane
Rinse the new CLARYN membrane under clean tap water for 30 seconds before insertion. Do not touch the membrane surface.
- 7
Insert the New Membrane
Insert the new membrane in the same orientation as the old one. Push firmly until it seats fully. The brine seal (rubber seal) should face the direction water enters.
- 8
Reassemble and Pressurize
Replace and tighten the housing cap (clockwise) with the wrench — snug but not over-tightened. Open the feed water valve.
- 9
Check for Leaks
Inspect all connections for leaks. Let the system fill the storage tank (first fill may take 2–4 hours). Check connections again after initial fill.
- 10
Flush the New Membrane
Discard the first 2 full tanks of water from the new membrane. This flushes any storage preservatives and brings the membrane to full performance.
Do not use the first 2 tanks of water for drinking. Use them for watering plants or cleaning.
Common Mistakes to Avoid
Inserting the membrane in the wrong orientation — always verify with your system manual
Forgetting to flush 2 full tanks before use — results in unusual taste from membrane preservatives
Over-tightening the housing cap — hand-tight plus quarter turn is usually sufficient
Not replacing pre-filters — always replace sediment and carbon filters at the same time as the membrane
Skipping the leak check — a small drip can cause significant damage over time