Why Does Reverse Osmosis Water Tastes Metallic?

Why Does Reverse Osmosis Water Tastes Metallic?

Reverse osmosis water tastes different from non-filtered drinking water. However, it should never taste metallic. Most people describe the taste of RO water to be slightly acidic, neutral, or having no taste at all. This is largely due to the fact that reverse osmosis filters remove 92-99% of minerals that give water its taste.

A metallic taste usually occurs as a result of high levels of Total Dissolved Solids (TDS) or a low pH present in RO water. This is usually an indication that your RO system isn’t balanced or working properly.

Those that drink RO water can quickly tell when the water isn’t just right. This is because any taste in water, whether it be salty, bitter, or metallic is quite noticeable and acts as an early warning sign that your RO unit isn’t functioning properly. If this is an issue you are currently facing with your RO water, you have landed in the right place to get all the answers you need!

Read my comprehensive article about reverse osmosis.

3 Common Reasons Why RO Water Tastes Metallic

Reverse osmosis filtration systems are designed to remove all forms of metallic substances found in the water during the filtration process. The system is also designed to filter out all TDS and other ions present in water which includes sulfate, bicarbonates, and chloride. This is why RO water is widely regarded as the purest and safest water for drinking.

It is when a reverse osmosis system fails to successfully remove impurities that it can result in the water tasting weird or unpleasant. Failure of the RO system can also cause your water to give off a bad odor and compromise its quality making it unsafe for consumption.

In such an instance, the first thing you should do is conduct a water test to check for pH, lead, copper, iron, manganese, zinc, corrosion, TDS, and other metals.

Conducting a water test for all these metallic substances is crucial to understanding what types of metals are present in the water and where they might be coming from.

Here are three common reasons why your RO water tastes metallic:

1. High levels of iron

If the water test results show high levels of iron, this could be an indication that your filters aren’t working properly.

It is also quite likely that iron is finding its way into your purified drinking water due to corrosion or rust present around the drainage and faucet area or in your water pipes.

2. Low pH

Your reverse osmosis water should have a pH reading of 5 – 7 to be considered safe and healthy for drinking. A low pH reading is an indication that the RO water has become too acidic.

In such a case, the acidic water is likely causing the corrosion of copper tubing commonly found in residential plumbing systems. Low pH conditions are likely where the metallic taste is coming from.

3. High levels of total dissolved solids (TDS)

High levels of TDS can also result in metallic-tasting water. If your test results show high levels of particulates present in your purified water, your filters likely need replacing or there is an issue with the RO membrane.

It is important to remember that even though reverse osmosis systems are reliable and durable they are by no means bullet-proof. They require regular maintenance and care to ensure they are running at 100% efficiency.

How To Get Rid of Metallic Taste?

To get rid of the metallic taste the first thing you should do is carefully inspect your RO filtration system to pinpoint the source of the issue at hand.

This means checking your pre-filters, tubing, piping, and membrane.

1. Replace filters

If the filters seem to have reached their filtration capacity replace them immediately as this could very well be the cause of the metallic taste.

Clogged or worn-out filters can allow TDS to pass through and this is why filters must be sanitized and replaced regularly. Most filters need to be replaced every 4 to 4 months.

2. Change tubes if necessary

Check to see if there are any traces of corrosion in the tubes and fittings of your RO unit. If you have copper tubing replace it with polyethylene tubing as this material is a lot more resistant to salts, alkalis, and acids.

3. Re-Mineralize water

If the metallic taste is due to low pH, you should consider opting for an RO system that offers a re-mineralization feature. These systems add important minerals back into the water after purification, helping increase pH, and making the water taste a lot less acidic.

4. Replace membrane

If the issue doesn’t seem to be because of any of the above, it would be a good idea to check the membrane. A membrane is designed to last for 2 – 5 years depending on use, however, in some cases, it could fail earlier than expected giving your RO water that metallic taste.

Frequently Asked Questions?

Q) Why does my RO water taste salty, sour, or bitter?

Apart from tasting metallic, RO water can also taste salty, sour, or bitter. A bitter taste is due to increased amounts of carbon dioxide present in water which increases its pH. A salty or sour taste usually occurs when high levels of chloride ions and/or sodium sulfates are present in water.

Q) Why does my RO water taste like unfiltered tap water?

If your RO water tastes like tap water this is a telltale sign that the RO membrane is damaged and not working. What you are drinking is essentially the water coming from your public water system. Replacing the membrane will solve this issue.

Q) Why does my RO water taste & smell like rotting eggs?

The last thing anyone wants is for their drinking water to smell or taste foul. However, this can happen if there is high sulfur content in the water. Once again, the culprits here are most likely the filters and/or the membrane.

Final Thoughts

Just like any other water purification system, a reverse osmosis system is also prone to malfunctioning over time. As such, it is essential to keep your RO system well-maintained and sanitized. Changing filters once or twice a year, replacing the membrane every 2-4 years, and having the system serviced every quarter will ensure that your RO water is of the highest quality – whenever you fancy pouring yourself a glass!

Chief Guru

Richard Boch is a chemical engineer responsible for designing water filtration systems for industrial and residential customers. He has more than 20 years of experience with ion exchange, activated carbon, and reverse osmosis. Richard's expertise has made him a go-to source for municipalities and businesses looking to improve their water quality. When he's not working, Richard enjoys spending time with his wife and two young children. You can also follow him on LinkedIn, Twitter and Facebook.

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