Understanding Total Dissolved Solids (TDS)
Total Dissolved Solids (TDS) is a measurement of the total concentration of inorganic salts and organic matter dissolved in water, expressed in parts per million (ppm) or milligrams per liter (mg/L). These dissolved solids can include beneficial minerals like calcium and magnesium, as well as potential contaminants such as heavy metals and pollutants. While a TDS reading indicates the overall concentration, it does not identify the specific substances present.
How Water Purification Affects TDS
Water purification methods, particularly Reverse Osmosis (RO), significantly impact TDS levels. RO systems push water through a semi-permeable membrane to remove contaminants, which also strips away most minerals. This is effective for water with high TDS (over 500 ppm) but can result in very low TDS levels, sometimes as low as 25 ppm, when used on water that is already relatively clean.
The Pros and Cons of Drinking 25 TDS Water
The Benefits: Highly Purified Water
- High Purity: Water with a TDS of 25 is highly pure and largely free from contaminants like bacteria, viruses, and heavy metals.
- Specific Medical Needs: In certain medical situations where low mineral intake is required, ultra-pure water may be advised by a healthcare professional.
The Drawbacks: A Lack of Essential Minerals
While safe from many contaminants, consistently drinking water with a TDS of 25 can have long-term health considerations due to its low mineral content:
- Mineral Deficiency: Essential minerals like calcium, magnesium, and potassium, vital for various bodily functions, are largely absent in ultra-low TDS water. The body typically obtains these minerals from both food and water.
- Electrolyte Imbalance: Minerals function as electrolytes. Water with very low TDS does not contribute to maintaining this balance, which is important for overall health, especially for active individuals.
- Taste: The lack of dissolved minerals in highly purified water often results in a less appealing or flat taste, which might discourage adequate hydration.
- Potential Corrosiveness: Water with a low concentration of dissolved solids can be more corrosive and may potentially leach metals from plumbing systems over time.
Comparison of Water with Different TDS Levels
| Feature | Low TDS Water (<50 ppm) | Optimal TDS Water (50–300 ppm) | High TDS Water (>500 ppm) |
|---|---|---|---|
| Purity | Very high due to extensive filtration (e.g., RO). | Balanced; removes most contaminants while retaining minerals. | May contain high levels of contaminants like salts, heavy metals, and pollutants. |
| Mineral Content | Very low to non-existent; lacks essential minerals. | Contains a healthy balance of beneficial minerals like calcium and magnesium. | High mineral content, but may be dominated by undesirable or harmful elements. |
| Taste | Often described as flat, bland, or metallic. | Tastes crisp, clean, and more natural. | Can taste salty, bitter, or metallic, depending on the composition. |
| Long-Term Health | Potential risk of mineral deficiencies if not compensated by diet. | Supports health by providing beneficial minerals. | Potential health risks depending on the specific contaminants present. |
| Best Use | Short-term consumption or for specific medical needs. | General daily consumption for optimal health and taste. | Requires filtration before consumption to reduce potential risks. |
How to Achieve Optimal TDS Levels
If your water purification system, particularly an RO system, consistently produces water with a TDS of 25 ppm, you can adjust it to achieve a more optimal mineral balance:
- Install a TDS Controller: Some RO systems have a TDS controller or blending valve that allows a small amount of unfiltered water to be mixed back in to increase the mineral content to a desired level.
- Use a Remineralization Filter: A remineralization cartridge can be added after an RO system to reintroduce beneficial minerals such as calcium and magnesium.
- Add Mineral Drops: Trace mineral drops or liquid supplements can be added to water to quickly and easily restore mineral content.
- Add Mineral-Rich Salt: A small amount of unprocessed mineral-rich salt, like Himalayan sea salt, can add trace minerals and improve the taste without making the water salty.
Conclusion
While 25 TDS water is highly pure and safe in terms of many contaminants, it lacks the essential minerals that contribute to long-term health and a more appealing taste. For daily consumption, water with a balanced TDS level, typically between 50 and 300 ppm, is generally recommended. If your water purifier produces ultra-low TDS water, consider implementing methods to add beneficial minerals back into the water to ensure it provides both purity and nutritional value.
For further information on water quality guidelines, including TDS, the World Health Organization is an authoritative source.
