5 Ways to Tell if Your RO Membrane is Bad

The average lifespan of an RO membrane is 1-2 years, and it doesn’t typically require regular maintenance. However, it’s not uncommon for it to wear out and stop working properly.

If you suspect that’s the case with yours, we’re here to help you out. Below are tell-tale signs that your RO membrane needs replacing:

• Membrane discoloration
• Reduced flow rate
• Foul taste or smell
• Lukewarm water
• Cloudiness in the membrane

We’ll discuss all of these issues and what you can do about them. We’ll also examine how long RO membranes last, what causes damage to them, and how much it costs to replace them. 

1. Discoloration Is a Sign of a Bad Membrane

As the membrane filters incoming water, impurities in the water are left behind and coat its contact surface. If these impurities aren’t removed or regularly washed away during the RO process, they can build up and change the color of the membrane.

One quick way to tell if your membrane is discolored is to look inside your water filtration system. The membrane is a part of the system that is left exposed to air, so you should be able to tell if it’s stained or discolored.

If it’s discolored, it should immediately be replaced to prevent further damage.

2. Reduced Flow Rate Might Be a Sign Of a Faulty Membrane

A reduced flow rate could mean that your membrane is either clogged or is allowing too much water to pass through it. If the membrane is clogged, it will be unable to block larger contaminants, resulting in low water flow.

If the membrane allows too much water to pass through, it could be due to either a buildup of impurities or a breakdown of the membrane itself.

A clogged or faulty membrane can be corrected by thoroughly cleaning it. If the membrane is still clogged after cleaning, then you should consider replacing it.

3. A Foul Smell May Indicate a Bad Membrane

Over time, the RO membrane can become fouled by dirt, sediment, and other contaminants. When this happens, the membrane becomes less effective at removing impurities, and water produced by the system can have a bad taste or odor.

Unfortunately, cleaning the membrane may not be enough to remove the foul odor. You should consider replacing it.

4. Increased Water Temperature

If the filtration system is working as it should, the water that’s being pushed through should be lukewarm. If it suddenly gets hotter than lukewarm, it could indicate too much pressure is being applied to the system.

When there’s too much pressure, the membrane can start tearing. This causes water to be pushed back too quickly, resulting in a temperature rise.

Once again, the only solution is to replace the membrane. Otherwise, the water quality will only get worse.

5. Cloudiness In The Membrane

If you notice your RO membrane is beginning to develop a cloudy appearance, it could mean that it is contaminated with minerals. As minerals are pulled from the feed water, they can build up on the membrane and cause its performance to reduce.

If the membrane is cloudy, you need to clean or replace it before it damages the rest of the system.

How Long Does an RO Membrane Last?

With proper care and maintenance, an RO membrane can last 2-5 years. However, if left unchecked, several problems can shorten its lifespan.

To ensure your membrane lasts as long as possible, you must clean it regularly and check for signs of wear and tear that suggest it needs to be replaced. 

Additionally, the type of water being filtered can also impact the lifespan of an RO membrane. For example, water with a high mineral content can be more corrosive and reduce the filter’s longevity.

What Causes Damage to the RO Membrane?

Several factors can cause damage to an RO membrane, such as:

• An increase in differential pressure: This can happen when the system isn’t working correctly or there is a blockage.
• The back pressure phenomenon: This happens when water pressure in the system is too high, causing the membrane to rupture.
• Abrasion processes from fouling: This happens when deposits build up on the surface of the membrane and cause it to wear.
• Massive or micro-damage from scaling: This happens when deposits build up on the surface of the membrane and cause it to crack.

Oxidation processes and degradation with time can also cause damage to the membrane.

How Much Does an RO Membrane Replacement Cost?

The cost of replacement membranes can vary widely, from as little as $60 to more than $200 per year. The average price is typically between $80 and $90. The more filters your system has, the more expensive it will be to replace them.

How often you need to replace the membrane in your system depends on the make and model, and other factors like water usage, water contaminant levels, and feed water pressure. 

Summary

There are several ways to identify a bad RO membrane, such as discoloration, a sudden decrease in the flow rate, a foul taste or smell, increased water temperature, and cloudiness in the membrane.

There’s little you can do about a bad membrane. If you’ve tried cleaning it and that hasn’t worked, all you can do is replace it.