Is Your Drinking Water Safe? How to Check for TDS, Bacteria, and Heavy Metals at Home
Ensuring clean drinking water is essential for health, especially in India, where water contamination varies based on location. Many households rely on borewell, municipal, or tanker water, each with different levels of TDS (Total Dissolved Solids), bacteria, heavy metals, and sediments.
Before buying a water purifier, it is important to test your water quality to determine:
- Whether purification is necessary
- Which type of purifier (RO, UV, UF) is best for your home
This guide explains how to check TDS, bacteria, heavy metals, and chemical contaminants in water at home using simple testing methods, tools, and recommendations.
What is TDS (Total Dissolved Solids) in Water
TDS represents the total concentration of dissolved substances in water, including:
- Essential minerals such as calcium, magnesium, and potassium, which are beneficial for health
- Harmful contaminants such as arsenic, lead, and fluoride, which are toxic if above safe limits
Safe TDS Levels for Drinking Water (As Per BIS and WHO Standards)
| TDS Level (ppm) | Water Quality | Safe for Drinking |
|---|---|---|
| Below 50 ppm | Very low minerals, flat taste | Not ideal, lacks essential nutrients |
| 50 – 150 ppm | Soft, best for health | Ideal drinking water |
| 150 – 300 ppm | Slightly hard, acceptable | Safe to drink |
| 300 – 500 ppm | Moderately hard | Acceptable but may need filtration |
| 500 – 1200 ppm | High TDS, may contain harmful salts | Needs RO purification |
| Above 1200 ppm | Very hard, unsafe | Not recommended for drinking |
Water with TDS above 500 ppm should be purified using RO filtration.
How to Check TDS in Water at Home
Method 1: Using a Digital TDS Meter
This is the most accurate and easy method for home testing.
- Purchase a TDS meter, available for Rs. 200-500
- Fill a clean glass with tap water
- Turn on the TDS meter and insert it into the water
- Wait for 10-15 seconds and note the reading
Interpreting Your TDS Test Result
- Below 200 ppm: Safe for drinking, use a UV or UF purifier
- 200 – 500 ppm: May need RO+UV depending on contamination
- Above 500 ppm: RO purification is necessary
Method 2: Checking TDS Using Conductivity-Based TDS Strips
- Low-cost option (Rs. 100-300)
- Uses color change to estimate TDS
- Not as precise as a TDS meter
Steps to Use
- Dip the TDS test strip into water
- Compare the color change with the provided reference chart
Method 3: Lab Testing for TDS and Full Water Analysis
- Best for testing heavy metals and chemicals
- Provides accurate and reliable results
Steps
- Collect a clean water sample
- Send it to a government-approved BIS-certified lab
- Receive a detailed report on TDS, bacteria, and chemical contamination
The Indian government provides BIS-certified water testing services. Check with your local municipality for availability.
How to Check for Bacteria, Viruses, and Other Contaminants
Testing for Bacteria and Viruses in Water
Boiling Test
- Boil water for 15-20 minutes
- If sediments appear, the water has impurities
- If the water smells bad after cooling, it may contain bacteria or organic contamination
Home Water Testing Kits
- Cost: Rs. 300 – 700
- Uses chemical reagents to detect bacteria
- If the color turns dark or cloudy, the water is unsafe
Professional Lab Test
- Government and private labs offer microbial testing
- Tests for bacteria, viruses, and parasites
If bacteria are found, UV purification is required.
Testing for Heavy Metals and Chemicals (Arsenic, Lead, Fluoride, etc.)
DIY Chemical Test Kits
- Available online (Rs. 500 – 1500)
- Uses color-based indicators to detect lead, fluoride, or arsenic
Professional Lab Testing
- Tests for arsenic, lead, nitrates, pesticides, and other contaminants
- Cost: Rs. 500 – 3000
If heavy metals are present, only RO purifiers can remove them.
How to Interpret Your Water Test Results
| Water Issue | TDS Level | Recommended Solution |
|---|---|---|
| Low TDS, No Bacteria | Below 200 ppm | UV or UF purifier |
| Bacteria Found | Any TDS | UV Purifier Required |
| High TDS (Salty Taste) | Above 200 ppm | RO Purifier Needed |
| Heavy Metals (Arsenic, Lead, Fluoride) | Any TDS | RO with Heavy Metal Removal |
| Sediments and Dirt | Any TDS | UF Purifier Needed |
Avoid RO if TDS is below 200 ppm, as it removes beneficial minerals.
Where to Get Professional Water Testing in India
Government-Approved BIS Water Testing Labs
- Municipal water departments offer low-cost or free testing
- Check the Bureau of Indian Standards (BIS) website for lab listings
Private Water Testing Labs
- NABL-certified labs like SGS India, Eurofins, and others
- Cost: Rs. 500 – 3000 for full analysis
RO service providers also offer TDS and bacteria testing before recommending a purifier.
Choosing the Right Water Purifier Based on Test Results
| Test Result | Recommended Purifier |
|---|---|
| TDS Below 200 ppm, No Bacteria | UV or UF Purifier |
| TDS Above 200 ppm | RO Purifier Required |
| Bacteria or Viruses Found | UV Required |
| Heavy Metals Detected | RO with Heavy Metal Removal |
| Visible Dirt or Sediments | UF Required |
Test first, then decide. Do not buy an RO purifier unnecessarily.
Final Buying Guide: How to Choose the Right Purifier
- Step 1: Test your water with a TDS meter
- Step 2: Check for bacteria using home test kits
- Step 3: If TDS is below 200 ppm, avoid RO and use UV or UF
- Step 4: If TDS is above 200 ppm, choose RO
- Step 5: If heavy metals are found, get RO with metal removal filters
Conclusion: Why Every Indian Household Should Test Water
- Water contamination is common in India, making testing essential
- Avoid unnecessary RO purification, as it wastes water if not needed
- Use home test kits or lab services for better accuracy
- Choose the right purifier based on test results
Now you know how to check TDS and water quality at home. This will help you make an informed decision when selecting a water purifier.
