An increased demand for cleaner drinking water has seen reverse osmosis systems installed in households across the United States. However, a reverse osmosis system can sometimes wrongly produce cloudy water, which may also contain contaminants.
A reverse osmosis (RO) system produces cloudy because of poor maintenance, trapped air bubbles, improper installation of the system, or a damaged membrane. High water pressure or water with high mineral content can also create cloudy RO water.
This article will take you through the possible reasons reverse osmosis water may be cloudy and provide step-by-step instructions on how to solve each problem.
6 Reasons for Cloudy Reverse Osmosis Water
There are various reasons that can lead to an RO system producing cloudy water. Some have to do with system maintenance, while others are directly related to the water itself.
This guide applies to all reverse osmosis systems and will take you through each cause and solution for cloudy RO water step-by-step:
1. Air bubbles
The number one reason reverse osmosis water appears cloudy is because of trapped air bubbles. Air bubbles can become trapped in any component of an RO system, but is most common in the membrane housing or in the drain saddle.
Air bubbles typically become trapped in an RO system when the filters are changed or during original installation.
At first, the water will appear hazy, murky or cloudy due to the air bubbles. This isn’t something to be concerned about because air bubbles aren’t pollutants and won’t affect your water quality.
In fact, the water will clear up within a few minutes if this is the cause of your cloudy water. To confirm this:
- Take a clear glass of water.
- Open the RO faucet and pour water into the glass.
- Put it aside for a minute.
- The cloudiness will dissipate after one minute when the trapped air bubbles disappear.
Solutions.
- Remove the filters one-by-one and reinstall them carefully.
- Thoroughly clean all O-rings, drain saddle, drain tube, drain pipe, and the air gap hole to ensure there is no debris causing blockages.
- Run the RO faucet for 5 minutes on full pressure (you can collect the water and use it around the home, or in the garden so as not to waste it).
If your RO is also leaking it is likely a problem with the air gap or drain saddle. Water Purification Guide has detailed information on how to fix your RO if it is leaking available here.
2. High mineral content
More than 85% of American homes are supplied with hard water, so odds are high that your feed water is hard water. Hard water contains high concentrations of calcium and magnesium ions, which can make the water appear cloudy or even milky.
The calcium and magnesium can also appear as individual tiny white particles in your water – this is the calcium and magnesium joining with carbon and oxygen to form calcium carbonate or magnesium carbonate.
If you are unsure if your water is hard, greyish-white coatings on sinks and dishes and less foam in washing and soap use are strong indications of hard water.
Solutions
- There is no real solution to hard water, however there are two options. 1) invest in a water softener to remove the calcium and magnesium ions before the water enters your RO system, or 2) simply replace your RO membrane (and filters) more frequently than recommended.
- The calcium and magnesium are not considered harmful and while they damage your membrane and filters over time, their regular replacement will likely outweigh the expense of a water softener.
3. Improper installation
One of the most common reasons why reverse osmosis water is cloudy is actually improper installation.
Reverse osmosis uses pressure to push water through the systems that contain a large number of components, filters and o-rings, with each requiring correct installation to ensure efficient water purification and also to prevent damage or leakages.
When changing filters, or cleaning your reverse osmosis system, it’s important to ensure each component is correctly installed.
There are two ways cloudy water can be caused by improper installation:
- If the wrong type of faucet was fitted during installation, or if the faucet with an air gap between the RO system and the spout was installed incorrectly, contaminants and mineral ions can be pushed back into the water.
- If the filter housings are not correctly connected, unfiltered hard water can escape and enter the storage tank.
Solutions
- Go through each filter one by one and confirm it is fitted in correctly and tightly.
- Check each o-ring to for dust or debris before refitting snugly in place.
- Consult the user manual for your specific model or contact a qualified plumber if you are unsure how to correctly install the components of your RO system.
4. Poor maintenance
Poor system maintenance can also cause cloudy reverse osmosis water. All reverse osmosis systems need regular maintenance to be able to remove contaminants from your water efficiently and to maintain the flow rate of water at the faucet.
Failure to regularly maintain an RO system will ultimately lead to problems with its performance and the quality of the water produced.
Proper maintenance of an RO system includes replacing the filters and cleaning the storage tank (excluding tankless RO systems).
Infrequently (or never) cleaning the water tank can result in the accumulation of bacteria and dirt, which in turn can produce cloudy or murky water.
Replacing the filters regularly is also particularly important. Old filters become clogged and are unable to purify water efficiently, this inability to filter contaminants from your water can lead to cloudy (and contaminated) water coming out of your faucet.
No matter the brand, all reverse osmosis systems require filter replacement after a period of use, which varies between brands.
For example,
- Waterdrop recommends replacing filters every 3 months,
- Kent – 3 months,
- APEC – 6 to 12, and
- iSpring – 12 months.
However, don’t just rely on these generalized recommendations; watch the filter change indicator on your system to know when to change your filter(s), and don’t forget filter life varies depending on the quality of your water and the volume of water used. So if you are using more water (e.g., in the Summer) then you may need to change your filters more regularly.
Solutions.
- Schedule a regular maintenance routine for your RO system.
- Ensure you replace the filters on time. If you are unsure of how long it has been since you have changed the filters, then change them all now (including the semi-permeable membrane).
- Clean the storage water tank routinely. Again, if you are unsure of how long it has been since the tank was properly cleaned, take the time to do a deep clean. Use a 1:1 vinegar and water solution to thoroughly clean the tank.
To deep clean an RO water storage tank:
- Switch off the shut-off valve to turn off the water flow to the tank.
- Locate the incoming water pipe and disconnect it.
- Pull the tube away from the tank to disconnect it.
- To clean the tank, use a store-bought reverse osmosis sanitizer or a 1:1 vinegar and water solution for cleaning.
- Pour the cleaning solution into the reverse osmosis tank’s opening using a funnel.
- Allow 5 minutes for the solution to rest in the tank.
- Gently scrub the interior of the tank with a bottle brush.
- Pour the solution away and rinse it with clean water many times until the scent of the solution you used to wash it is gone.
- Allow it to dry and reconnect it for the next use.
5. Faulty membrane
A faulty membrane is another really common reason for cloudy RO water. If the semi-permeable membrane of an RO is damaged or clogged it will not function properly, and the contaminants in your water will simply pass through the system unfiltered – resulting in cloudy tap water.
After regular use, your RO membrane easily becomes blocked, especially if you live in a location with hard water. This is a not an unusual occurrence and just indicates that your membrane needs replacing.
Solutions
- Replacing the RO system membrane.
- If you live in an area with hard water you may want to consider investing in a water softener. This will prevent the calcium and magnesium ions in the hard water from damaging your RO membrane prematurely.
6. Water pressure
High water pressure from the water supply to the reverse osmosis system, tank, and faucet can cause cloudy RO water.
The ideal water pressure for a reverse osmosis system is approximately 60 psi but should not be greater than 80 psi.
Fortunately, this does not indicate contaminants, and the cloudiness disappears soon after the water settles in a glass for a few moments. This is because when water is compressed (placed under pressure), it forms tiny water bubbles, resulting in a carbonated effect that clouds the water.
This is also why, after you run the faucet for awhile the water that comes out of the tap can clear.
Solutions
- Double-check the faucets throughout your home to determine if the pressure is higher than normal elsewhere.
- Sometimes a pressure change can be the result of temperature changes, or your water supply undergoing maintenance – which are temporary problems.
- Invest in a water pressure regulator if the problem is ongoing.
Will reverse osmosis make my water crystal clear?
Reverse Osmosis systems are among the most effective water purification systems that can remove most contaminants from water. Using its purification stages, an RO system should be capable of removing up to 99% of pollutants, including odors and colors, making the water crystal clear.
What are the white particles in my reverse osmosis water?
The white particles in reverse osmosis water are mineral deposits such as calcium and magnesium caused by hard water. It is advised to install a water softener if you come from a hard water area to remove the calcium and magnesium ions before the water reaches the RO membrane.
