Reverse osmosis (RO) water itself does not directly damage pipes. However, the demineralized nature of RO water can make it more corrosive to certain types of plumbing materials over time, especially if the system isn’t properly maintained or if the water has other aggressive properties.
Understanding RO Water and Pipe Interactions
Reverse osmosis systems produce highly purified water by removing a vast majority of dissolved solids, minerals, and contaminants. While this purification is excellent for drinking water quality, it fundamentally changes the water’s chemical composition.
Why is RO Water Potentially Corrosive?
Pure water, devoid of minerals, has a natural tendency to seek out and dissolve substances to achieve equilibrium. This means it can leach minerals from the very pipes it flows through.
- Lack of Buffering Minerals: Minerals like calcium and magnesium, normally present in tap water, act as natural buffers. They can form a protective scale on the inside of pipes, shielding the metal from direct contact with the water. RO water lacks these buffers.
- Lower pH: The demineralization process can sometimes lead to a slightly lower pH in RO water, making it more acidic. Acidic water is inherently more corrosive to metals like copper and lead.
- Dissolved Gases: If the RO system isn’t properly sealed, it can absorb dissolved gases like carbon dioxide from the air. When this CO2 dissolves in water, it forms carbonic acid, further increasing corrosivity.
What Types of Pipes Are Most at Risk?
The impact of RO water on pipes depends largely on the plumbing material and its condition.
- Copper Pipes: Older copper pipes, especially those with a thin protective layer, may be more susceptible to leaching and pitting from prolonged exposure to aggressive RO water. This is a gradual process, not an immediate failure.
- Lead Pipes: While lead pipes are a concern for drinking water quality regardless of the water source, highly demineralized water can exacerbate the leaching of lead. However, most modern plumbing systems do not use lead pipes.
- Plastic Pipes (PVC, PEX): Generally, plastic pipes are much more resistant to the corrosive effects of RO water. They do not contain metals that can be leached.
Mitigating the Risk: Protecting Your Plumbing
Fortunately, there are several effective ways to prevent potential pipe damage when using an RO system. These strategies focus on re-mineralizing the water or adjusting its chemical properties.
Re-mineralization Cartridges
Many RO systems offer an optional re-mineralization filter as a post-filter. This cartridge contains natural minerals like calcite or coral calcium.
- As the RO water passes through, these minerals are dissolved into the water.
- This process raises the pH and adds back beneficial minerals.
- It effectively neutralizes the water’s aggressive nature, making it less corrosive.
pH Adjustment Filters
Similar to re-mineralization, some filters are specifically designed to adjust the pH of RO water. They use alkaline minerals to increase the pH, making the water less acidic and therefore less likely to corrode pipes.
Regular System Maintenance
Proper maintenance of your RO system is crucial. This includes:
- Regular Filter Changes: Replacing filters on schedule ensures optimal performance and prevents the buildup of contaminants that could affect water chemistry.
- Checking for Leaks: Ensuring the system is properly sealed prevents the absorption of atmospheric gases.
- Periodic Water Testing: If you have concerns or older plumbing, periodically testing your RO water’s pH and TDS (Total Dissolved Solids) can provide valuable insights.
Consider Your Existing Plumbing
If you have older plumbing, especially copper, it’s wise to be proactive. Installing a re-mineralization or pH adjustment filter is a small investment that can save you from potential future pipe issues.
Frequently Asked Questions About RO Water and Pipes
### Does RO water cause leaks in pipes?
RO water itself doesn’t directly cause leaks. Leaks typically occur due to physical damage, corrosion that thins pipe walls over time, or joint failures. While aggressive RO water can contribute to corrosion, it’s a slow process and not an immediate cause of leaks.
### How can I test if my RO water is too corrosive?
You can test for corrosivity by measuring the pH and Total Dissolved Solids (TDS) of your RO water. A pH below 7.0 and a very low TDS (typically below 50 ppm) can indicate aggressive water. You can purchase home testing kits or send a sample to a lab for more comprehensive analysis.
### Is it safe to drink RO water if I have older pipes?
It is generally safe to drink RO water, but if you have older plumbing (especially lead or very old copper), it’s advisable to use a post-filter that re-mineralizes or adjusts the pH. This makes the water less likely to leach metals from your pipes into your drinking water.
### What is the ideal TDS level for RO water to prevent pipe damage?
Ideally, RO water should have a TDS level between 50-150 ppm to be less aggressive towards plumbing. Re-mineralization filters are designed to bring the TDS into this range, making the water safer for your pipes and also more palatable for drinking.
Conclusion: Protecting Your Investment
While the concern about RO water damaging pipes is valid, it’s important to understand that the risk is manageable. By implementing simple solutions like re-mineralization filters and ensuring proper system maintenance, you can enjoy the benefits of purified RO water without compromising the integrity of your plumbing.
If you’re considering an RO system, discuss your existing plumbing with the installer. They can help you choose the right configuration, including necessary post-filters, to ensure a safe and effective water purification solution for your home.