Is 25 TDS Safe for Drinking Water?

Total Dissolved Solids (TDS) have become a buzzword for every household using water purifiers. As more people shift to RO systems, the question arises: is 25 TDS safe for drinking water?

This guide helps you understand what TDS means, the role it plays in drinking water quality, and whether ultra-low TDS, such as 25 ppm, is good or bad for long-term health.

What Is TDS in Drinking Water?

TDS stands for Total Dissolved Solids, which includes organic salts, minerals, and small amounts of natural and man-made substances dissolved in water. Common components include:

• Calcium

• Magnesium

• Potassium

• Sodium

• Chlorides

• Sulfates

TDS is measured in parts per million (ppm) or milligrams per liter (mg/L). The higher the number, the more substances are dissolved in your water.

But not all dissolved solids are harmful—many are essential for human health.

Why Does TDS Matter in Purified Water?

Water that’s too high in TDS can taste salty, metallic, or even bitter. On the other hand, water with very low TDS may lack essential minerals, resulting in:

• Bland or flat taste

• Increased acidity

• Lack of essential electrolytes

This is particularly relevant for households using RO (Reverse Osmosis) systems, which are excellent at filtering but sometimes reduce TDS excessively—often down to 25 or even lower.

What Happens If TDS Is Too Low?

Water with a TDS level of 25 ppm or below is considered “ultra-purified”. While that may sound ideal, it's not always the healthiest choice.

Potential Issues with Very Low TDS Water:

1. Mineral Deficiency: Essential minerals like calcium and magnesium are removed.

2. Flat Taste: Water may taste bland or “dead” due to absence of natural minerals.

3. Corrosive Nature: Extremely pure water can leach metals from pipes.

4. Electrolyte Imbalance: Especially for people with higher physical activity levels.

Though not harmful in the short term, long-term consumption of very low TDS water can lead to nutrient gaps unless minerals are supplemented in other ways.

Is 25 TDS Safe for Drinking Water?

The short answer is: Technically, yes—but it’s not ideal.

A TDS level of 25 ppm is not dangerous but lacks the necessary minerals to support your body’s daily needs. The Bureau of Indian Standards (BIS) recommends a TDS range between 50–300 ppm for optimal drinking water quality.

Why 25 TDS Isn’t Optimal:

• No harmful chemicals, but also no beneficial minerals

• Doesn’t support electrolyte balance

• Unappealing taste profile

• Long-term use may require re-mineralization

If your water has a TDS of 25, you’re drinking clean water, but not mineral-rich water.

What Is the Ideal TDS for Drinking Water?

Let’s break down the recommended TDS ranges for drinking water:

In summary, 50–150 ppm is widely accepted as the ideal TDS range for drinking water.

Why Does RO Water Have Very Low TDS?

Reverse Osmosis (RO) systems are engineered to remove up to 90–95% of TDS from source water. This is excellent when the input water has very high TDS (500+ ppm), such as in borewell water. But if the source water is already moderate (say 200–300 ppm), RO can bring it down to 25 ppm or lower.

How RO Reduces TDS So Much:

• Multi-stage filtration

• Use of semi-permeable membrane

• Filters out salts, metals, fluoride, nitrates

Unless you control the TDS output with a TDS controller or a mineral cartridge, most RO systems default to ultra-low TDS output.

Minimum TDS Level for Drinking Water

According to BIS and global health bodies:

• Minimum Acceptable TDS: 50 ppm

• Optimal TDS Range: 75–150 ppm

• Above 500 ppm: Requires purification

• Below 50 ppm: May not support essential mineral intake

So, while 25 TDS is technically safe, it's below the healthy minimum.

How to Check and Adjust RO Water TDS

1. Use a TDS Meter:

These are affordable devices you can dip into a water glass to instantly check TDS. For accuracy, test RO water at the faucet.

2. Install a TDS Controller:

This feature in RO systems blends a small percentage of raw water back into the RO output to maintain mineral balance.

3. Add a Re-Mineralization Filter:

Mineral cartridges add calcium, magnesium, and other nutrients back into purified water.

4. Avoid Over-purifying Water:

If your input TDS is already below 300 ppm, consider using UF or UV filters instead of RO.

Long-Term Health Effects of Drinking 25 TDS Water

While short-term consumption is safe, prolonged exposure to ultra-pure water may:

• Reduce mineral absorption

• Affect bone strength and dental health

• Lead to dry skin or hair

• Cause fatigue (due to low electrolyte levels)

People with certain health conditions (e.g., kidney issues) may be more sensitive to mineral imbalances.

Is It Better to Drink Slightly Higher TDS Water?

Yes. Water in the 75–150 ppm range:

• Tastes better

• Supports better hydration

• Includes naturally occurring minerals

• Is gentle on your body over time

Most natural springs and wells offer water in this range.

Also Read - What is the Minimum TDS for Drinking Water? A Complete Guide

Summary: Should You Drink Water with 25 TDS?

Final Thoughts

TDS is not just a number—it’s a key indicator of water quality, health, and taste. While RO systems do an excellent job of removing contaminants, they can sometimes over-purify water.

If your RO output is showing 25 TDS, it’s time to check if you need mineral boosters or a TDS controller to bring your water into the optimal health range.

Choosing the right TDS level ensures your water is not only clean but also nourishing.

FAQs

Is 25 TDS safe for daily drinking?

Yes, it’s technically safe, but not ideal for long-term health due to lack of minerals.

What is the minimum TDS level for healthy drinking water?

Around 50 ppm is the minimum; 75–150 ppm is considered ideal.

How do I increase TDS in my RO water?

Install a TDS controller or re-mineralization filter to maintain healthy TDS levels.

Does 25 TDS water taste bad?

Many users report that ultra-low TDS water tastes flat, acidic, or metallic.

Can kids and elderly drink 25 TDS water?

While safe, it's recommended to ensure mineral-rich water for children and seniors.