🔧 RO Water Tastes Salty, Bitter or Metallic? Fix Membrane & Filter Issues
Problem Overview
Is your RO purified water suddenly tasting salty, bitter, or metallic when it used to taste pure and clean? Bad taste in RO water is a serious warning sign indicating membrane failure, exhausted post-carbon filter, TDS creep through damaged membrane, or mineral imbalance. This comprehensive guide helps you diagnose the exact cause using simple TDS testing, understand what each taste indicates, and provides step-by-step solutions specific to Indian water conditions and popular brands like Kent, Aquaguard, Pureit, Livpure, and HUL.
Safety & Health First
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Don't drink bad-tasting water: If RO water tastes significantly different, stop drinking it immediately. High TDS or contaminants may have breached the membrane.
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TDS testing is mandatory: Buy a TDS meter (₹200-₹500) and test output water. Output TDS >50 ppm indicates membrane failure or TDS creep - requires immediate filter service.
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Metallic taste = serious issue: Strong metallic taste could indicate heavy metal contamination if membrane is damaged. Get water tested professionally if taste is severe.
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Turn off water supply before maintenance: Always close inlet valve before opening any filter housing to prevent flooding and water contamination.
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Use only food-grade filters: Never use cheap, non-certified replacement filters as they can leach chemicals and cause bad taste or health issues.
🔍 Quick Diagnostic Checks ⏱️ 10-15 minutes
1 Test Output TDS Immediately
Use TDS meter to test RO output water. Ideal: <30 ppm. Acceptable: 30-50 ppm. Problem: >50 ppm. High TDS = membrane failure or bypass.
2 Compare Input vs Output TDS
Test input tap water TDS. Calculate rejection rate: (Input-Output)/Input × 100%. Should be >90%. If <80%, membrane is compromised.
3 Check Filter Replacement Dates
When was the last filter service? Post-carbon filter (taste/odor removal) lasts 12 months. RO membrane lasts 2-3 years. Overdue filters cause bad taste.
4 Smell and Taste Profile
Salty = high mineral TDS. Bitter = post-carbon exhausted or alkaline minerals. Metallic = membrane damage or pipe corrosion. Chlorine = pre-carbon failed.
5 Flush System Test
Drain storage tank completely and refill with fresh purified water. If taste improves, it was stagnant water. If still bad, it's a filter/membrane issue.
6 Check TDS Controller Setting
If your RO has TDS controller/mineralizer, check if setting was accidentally changed. High setting bypasses more input water, increasing TDS and causing salty taste.
📊 Understanding RO Water Taste & TDS Relationship
💡 What Each Taste Indicates About Your RO System
Different tastes point to specific failures. Use this guide to diagnose the exact problem before calling service.
| Taste Description | Typical Output TDS | Most Likely Cause | Urgency |
|---|---|---|---|
| Salty/Brackish | >80 ppm | RO membrane failure, TDS creep | 🚨 Urgent |
| Bitter/Alkaline | 30-60 ppm | Post-carbon filter exhausted, mineralizer issue | ⚠️ Replace Soon |
| Metallic/Iron-like | Varies | Membrane damage, pipe corrosion, heavy metals | 🚨 Stop Drinking |
| Chlorine/Chemical | <50 ppm | Pre-carbon filter saturated, post-carbon exhausted | ⚠️ Service Needed |
| Musty/Stale | <40 ppm | Bacterial growth in tank/pipes, post-carbon old | ⚠️ Sanitize System |
| Slightly Sweet/Flat | <20 ppm | Over-purification, very low TDS (normal for pure RO) | ✅ Normal |
TDS Rejection Rate Calculation (Important Diagnostic):
- • Formula: Rejection % = ((Input TDS - Output TDS) / Input TDS) × 100
- • Example: Input = 500 ppm, Output = 30 ppm → (500-30)/500 × 100 = 94% (Excellent)
- • Healthy membrane: 90-95% rejection rate
- • Aging membrane: 80-89% rejection rate (replace within 6 months)
- • Failed membrane: <80% rejection rate (replace immediately)
💡 Common Causes → Solutions
Problem
RO Membrane Failure/Damage (40% of taste issues)
Membrane pores enlarged or damaged due to age (>3 years), scaling from hard water, or chlorine damage. Output TDS >80 ppm, salty taste, rejection rate <80%.
Solution
Replace RO Membrane (Professional)
Urgent replacement needed. Cost: ₹1,500-₹4,000 (membrane) + ₹300-₹800 (labor). Choose brand-compatible or universal membrane. Taste improves instantly.
Problem
Exhausted Post-Carbon Filter (30% of cases)
Activated carbon saturated after 12+ months, loses ability to remove residual taste, odor, and organic compounds. Water tastes bitter, flat, or slightly chemical.
Solution
Replace Post-Carbon Filter (DIY or Pro)
Easy DIY replacement. Cost: ₹200-₹500 for filter. Replace annually. Improves taste immediately. Essential for taste/odor removal after RO.
Problem
TDS Controller/Mineralizer Malfunction
TDS controller valve stuck open or setting too high, allowing excessive bypass of unfiltered water. Output TDS 60-150 ppm, salty taste but membrane is actually fine.
Solution
Adjust or Bypass TDS Controller
Check controller knob/setting - reduce bypass. Or temporarily bypass controller to test if membrane is working. Professional adjustment: ₹300-₹800.
Problem
Stagnant Water in Storage Tank
Water sitting in tank for >7 days without use. Bacterial growth, biofilm formation, or taste from plastic tank. Musty, stale, or plastic taste.
Solution
Flush and Sanitize System (DIY)
Drain tank completely, run 2-3 full tanks to waste. Sanitize tank with food-grade disinfectant solution. Use water regularly (empty tank weekly). Easy DIY fix.
Problem
Pre-Carbon Filter Saturated
Activated carbon pre-filter exhausted, not removing chlorine/organics effectively. Chlorine reaches RO membrane, damages it, causes chemical taste and accelerated membrane failure.
Solution
Replace Pre-Carbon Filter
Replace every 6-12 months. Cost: ₹200-₹400. Prevents chlorine damage to membrane. Replace along with sediment filter for complete pre-filtration.
Problem
Metallic Taste from Pipe Corrosion or Heavy Metals
Old galvanized pipes corroding, or input water contains iron/copper/lead. Membrane damage allows heavy metals to pass. Serious health concern.
Solution
Professional Water Testing + System Upgrade
Get professional water testing (₹1,000-₹3,000). Replace membrane immediately. May need additional heavy metal removal filter. Replace old pipes. Do NOT drink water.
Problem
Sudden Input Water Quality Change
Municipal supply switched to bore water, or seasonal TDS spike (summer), or new contamination source. Overwhelms existing filters and membrane.
Solution
Test Input Water, Replace All Filters
Test input TDS. If >1500 ppm, need water softener or multi-stage pre-treatment. Replace all filters immediately (sediment, carbon, membrane if damaged). May need upgraded RO system.
Problem
UV Lamp or Alkaline Filter Cartridge Leaching
UV lamp quartz sleeve cracked leaching minerals, or alkaline/mineralizer cartridge over-dosing minerals into water. Bitter, chalky taste, slightly high TDS.
Solution
Replace UV Sleeve or Adjust Mineralizer
Check UV lamp chamber for cracks. Replace quartz sleeve (₹300-₹800). If mineralizer cartridge is old (>12 months), replace it. Taste returns to normal immediately.
🛠️ DIY Diagnostic Steps You Can Try Now
Test TDS Levels (Input vs Output)
What you need: TDS meter (₹200-₹500 from Amazon/local electronics shop). Essential tool for RO troubleshooting.
Step-by-step:
- 1. Rinse TDS meter probe with clean water
- 2. Fill a clean glass with tap water (input water)
- 3. Insert TDS meter probe, wait for reading to stabilize (10-15 seconds)
- 4. Note input TDS reading (e.g., 450 ppm)
- 5. Rinse probe again with RO water
- 6. Fill glass with RO purified water from tap (run for 10 seconds first to clear pipe)
- 7. Insert probe, wait for stable reading
- 8. Note output TDS reading (e.g., 35 ppm)
- 9. Calculate rejection: (450-35)/450 × 100 = 92% (Good!)
- 10. If output TDS >50 ppm or rejection <80%, membrane is compromised
Flush System to Rule Out Stagnant Water
Why this works: If water sits in storage tank for >7 days, it can develop stale taste from biofilm or bacterial growth. Flushing tests if it's a filter problem or storage problem.
Step-by-step:
- 1. Turn off inlet water supply to RO system
- 2. Open RO tap and drain storage tank completely (8-10 liters)
- 3. Turn inlet water supply back on
- 4. Let system refill tank completely (1-2 hours)
- 5. Drain first 2 liters from refilled tank to waste (clears pipes)
- 6. Taste the next glass of water
- 7. If taste is now normal, it was stagnant water issue (easy fix - use water regularly)
- 8. If taste is still bad, it's a filter/membrane problem (proceed to filter replacement)
Replace Post-Carbon Filter (Easiest DIY Fix)
When to try: If TDS is normal (<50 ppm) but water still tastes bitter, flat, or slightly chemical. Post-carbon filter is the final stage that removes residual taste/odor.
What you need: Replacement post-carbon filter (₹200-₹500), filter wrench (usually provided with RO), bucket, clean cloth.
Step-by-step:
- 1. Turn off inlet water supply valve
- 2. Close storage tank valve (usually a blue knob on top)
- 3. Open RO tap to release pressure
- 4. Locate post-carbon filter (final stage, usually inline filter after tank)
- 5. Place bucket under filter to catch water spillage
- 6. Use filter wrench or hands to unscrew filter housing (counterclockwise)
- 7. Remove old filter cartridge, check O-ring for damage
- 8. Insert new post-carbon filter (check arrow direction for flow)
- 9. Apply thin layer of food-grade silicone grease to O-ring
- 10. Screw housing back hand-tight (don't over-tighten)
- 11. Open inlet valve and tank valve, check for leaks
- 12. Flush 1-2 liters of water to waste before drinking
- 13. Taste should improve immediately if post-carbon was the issue
Check and Adjust TDS Controller Setting
What it is: Some RO systems have TDS controller (also called mineralizer) that bypasses a small amount of input water to mix with RO water, adding minerals. If set too high, causes salty taste.
How to check:
- 1. Look for a small knob or valve labeled "TDS controller" or "Mineralizer" on your RO unit
- 2. Not all RO systems have this - Kent, Livpure, some Aquaguard models have it
- 3. Current setting: note knob position (usually 1-5 scale or clockwise/counterclockwise)
- 4. Test current output TDS with meter
- 5. Turn knob counterclockwise (reduces bypass, lowers TDS)
- 6. Drain storage tank completely and refill
- 7. Test output TDS again - should be lower now
- 8. Taste the water - should be less salty
- 9. Ideal output TDS: 30-50 ppm for good taste and mineral balance
- 10. If turning knob to minimum still gives >80 ppm, membrane is failed (not TDS controller issue)
Sanitize Storage Tank and Lines
When needed: If water tastes musty, stale, or "off" even with normal TDS. Indicates bacterial biofilm growth in tank or pipes.
Sanitization process:
- 1. Turn off inlet water supply
- 2. Drain storage tank completely
- 3. Prepare sanitizing solution: 1 tablespoon household bleach (sodium hypochlorite) in 5 liters water OR use food-grade hydrogen peroxide solution
- 4. Pour sanitizing solution into tank through RO tap (disconnect from tank temporarily)
- 5. Let solution sit in tank for 30-60 minutes
- 6. Drain sanitizing solution completely
- 7. Rinse tank by refilling and draining 2-3 times with RO water
- 8. Refill tank normally and flush 2-3 liters before drinking
- 9. For severe biofilm, call professional for complete system sanitization (₹500-₹1,000)
📞 When to Call a Professional
🔧 Urgent Professional Service Required
- • RO Membrane Replacement
Cost: ₹1,500-₹4,000 (membrane) + ₹300-₹800 (labor)
Time: 45-60 minutes
When: Output TDS >80 ppm, rejection rate <80%, salty taste - • Metallic Taste Investigation
Cost: ₹1,000-₹3,000 (professional water testing)
When: Strong metallic/iron taste, suspected heavy metals
Action: Stop drinking water immediately - • Complete System Overhaul
Cost: ₹3,000-₹6,000 (all filters + membrane + service)
When: System >4 years old, multiple taste issues, no maintenance history
💰 Component Costs by Brand
- • Kent RO Membrane
75 GPD: ₹1,800-₹2,500 | 80 GPD: ₹2,200-₹3,000 - • Aquaguard/Eureka Forbes Membrane
₹2,500-₹3,500 (original), ₹1,500-₹2,000 (compatible) - • Pureit/Livpure Membrane
₹1,500-₹2,500 - • Universal Compatible Membranes
₹1,200-₹2,000 (DOW, Vontron, CSM brands) - • Post-Carbon Filter (all brands)
₹200-₹500
📋 What to Expect During Professional Service
Diagnosis Visit (₹200-₹500):
- • TDS testing of input and output water
- • Membrane rejection rate calculation
- • Visual inspection of all filters
- • Leak detection and pressure testing
- • Detailed quote for required repairs
Complete Service (₹1,500-₹3,000):
- • All filter replacements (pre + post)
- • Membrane replacement if needed
- • System sanitization and flushing
- • TDS controller adjustment
- • Final water quality testing
🇮🇳 Brand-Specific Troubleshooting Notes for Indian Market
💡 Different RO brands have specific quirks and common issues in Indian conditions
Understanding your brand's typical problems helps faster diagnosis and finding compatible replacement parts.
Kent Kent Grand+, Kent Supreme, Kent Pearl
Common taste issues:
- • TDS controller malfunction: Kent's TDS controller valve is prone to sticking. Symptoms: Suddenly salty water even with new membrane. Fix: Adjust TDS knob to minimum or bypass controller temporarily to test.
- • Post-carbon quick exhaustion: Kent's fine post-carbon filter saturates faster in hard water areas. Replace every 10-12 months instead of standard 12-15 months.
- • Membrane compatibility: Kent uses 75 GPD or 80 GPD membranes. Universal membranes work fine (DOW Filmtec, Vontron). Original Kent membrane: ₹2,200-₹3,000, Compatible: ₹1,500-₹2,000.
- • Mineralizer cartridge: Some Kent models have mineralizer cartridge that can over-dose minerals causing bitter taste. Replace every 12-18 months or remove if not needed.
Aquaguard Aquaguard Enhance, Magna, Delight (Eureka Forbes)
Common taste issues:
- • Taste Guard technology aging: Aquaguard's proprietary Taste Guard (post-carbon + mineral cartridge combo) needs replacement at 18-24 months. Bitter taste indicates exhaustion.
- • Service dependency: Aquaguard systems heavily locked to authorized service. Many filters are proprietary. Compatible universal filters available but check size carefully.
- • Membrane costs: Original Aquaguard membranes expensive (₹2,500-₹3,500). Compatible options (₹1,500-₹2,000) work well - use DOW, Vontron, or CSM brands.
- • AMC plans: Aquaguard pushes AMC plans heavily. If under AMC, taste issues should be covered - call for free service. Without AMC, service can be expensive.
Pureit Pureit Marvella, Copper, Vital (HUL)
Common taste issues:
- • Copper cartridge leaching: Pureit Copper models have copper charging technology. Old cartridge (>18 months) can over-leach copper causing metallic taste. Replace copper cartridge (₹800-₹1,200).
- • Germkill Kit dependency: Pureit uses proprietary "Germkill Kit" (RO membrane + post-carbon combo). Entire kit needs replacement (₹1,800-₹2,800) even if only membrane failed. Cannot replace membrane separately easily.
- • Filter alert system: Pureit has automatic filter alert. If tasting bad but alert hasn't triggered, reset system or check if alert mechanism is faulty.
- • Compact design limitations: Pureit's compact models have smaller membrane (50 GPD) which saturates faster in high TDS areas. May need more frequent replacement (18-24 months vs 30-36 months).
Livpure Livpure Glo, Touch, PEP Pro
Common taste issues:
- • Mineralizer over-dosing: Livpure's in-tank mineralizer can over-dose minerals if cartridge is old or faulty. Symptoms: Slightly bitter, chalky taste, output TDS 50-80 ppm. Fix: Replace mineralizer cartridge (₹400-₹700) or disable if not needed.
- • Silver nano technology: Some Livpure models use silver-charged post-carbon. Old cartridge can leach silver particles causing slightly metallic taste. Replace post-carbon every 12 months.
- • Easy filter access: Livpure designs allow easy DIY filter replacement. Good for DIY post-carbon replacement. Filters widely available online (₹200-₹400).
- • Membrane compatibility: Livpure uses standard 75 GPD membranes. Universal membranes work perfectly. Original Livpure membrane (₹1,800-₹2,500), Universal (₹1,200-₹1,800).
Generic/Unbranded Local Assembly RO Systems
Common taste issues:
- • Low-quality filters: Generic systems often use cheap, non-certified filters that leach chemicals or break down quickly. Taste problems more common. Solution: Upgrade to branded certified filters (DOW membrane, NSF-certified carbon filters).
- • Improper assembly: Incorrect filter sequence or bypass plumbing can cause taste issues. Example: Post-carbon installed before RO membrane instead of after. Check filter sequence.
- • Advantage - easy DIY: No proprietary parts. Easy to replace with standard universal components. All filters and membranes available online at lower prices.
- • TDS controller confusion: Many generic systems have TDS controller but it's not labeled or explained. Check for small bypass valve and test by closing it completely to see if TDS drops.
🛡️ Preventive Care to Maintain Good Taste
Every 6-12 Months
Replace pre-filters (sediment + pre-carbon) and post-carbon filter. Cost: ₹600-₹1,200. Prevents taste issues before they start. Hard water areas: every 6 months.
Every 2-3 Years
Replace RO membrane proactively before complete failure. Cost: ₹1,500-₹4,000. Don't wait for salty taste - replace when rejection rate drops to 85-90% or after 30-36 months.
Monthly Checks
Test output TDS monthly with meter (₹200-₹500). Drain tank weekly if not using regularly. Taste test your water - catch problems early before health risk.
Best Practices to Prevent Bad Taste:
- ✓ Use water regularly: Empty tank at least once a week to prevent stagnation
- ✓ Monitor input water quality: Test input TDS monthly, if suddenly high (>1000 ppm), add water softener
- ✓ Flush after long breaks: After >5 days without use, drain tank completely and refill before drinking
- ✓ Sanitize tank annually: Professional sanitization every 12 months (₹500-₹1,000) or DIY with bleach solution
- ✓ Use only certified filters: Avoid cheap, non-food-grade replacement filters that can leach chemicals
- ✓ Mark replacement dates: Label each filter housing with installation date using permanent marker
- ✓ Annual professional check: Even if tasting fine, get annual service (₹800-₹1,500) for TDS check, leak inspection, filter condition
- ✓ TDS meter ownership: Buy your own TDS meter (₹200-₹500) - don't depend on service technician's claims
❓ Frequently Asked Questions
Q: My RO water suddenly tastes salty but TDS meter shows only 45 ppm. What's wrong?
Answer: TDS 45 ppm is actually fine, so it's not membrane failure. Most likely causes: (1) Post-carbon filter exhausted - can cause slightly salty/bitter taste even with normal TDS. Replace post-carbon filter (₹200-₹400). (2) TDS controller adding concentrated minerals - if your RO has mineralizer, it might be over-dosing. Turn mineralizer knob to lower setting or bypass it. (3) Stagnant water in tank - if water sat for >7 days, drain tank completely and refill. (4) Your taste perception changed - pure RO water (<30 ppm) tastes very flat; 45 ppm might seem salty in comparison. If you recently switched from bottled water to RO, taste adjustment period is normal. Test by comparing with bottled RO water.
Q: RO water has strong metallic taste. Is it safe to drink? Should I be worried?
Answer: Do NOT drink water with strong metallic taste - this is potentially dangerous. Metallic taste indicates: (1) RO membrane completely failed - allowing heavy metals (iron, copper, lead, arsenic) from input water to pass through. Very high health risk. (2) Corroded pipes/fittings - old galvanized pipes leaching metals into water. (3) Input water contamination - bore water with high iron/manganese. Immediate actions: (a) Stop drinking this water immediately; (b) Test output TDS - if >100 ppm, membrane is failed; (c) Get professional water testing for heavy metals (₹1,000-₹3,000); (d) Replace RO membrane urgently (₹1,500-₹4,000); (e) If pipes are old (>20 years), consider pipe replacement; (f) Use bottled water until RO is fixed and tested safe. Metallic taste is NOT a minor issue - treat it as emergency.
Q: How can I tell if I need to replace the membrane or just the post-carbon filter?
Answer: Use this decision tree: Step 1 - Test TDS: Test output TDS with meter. If output TDS <50 ppm: Membrane is fine, problem is post-carbon filter or taste perception. Replace post-carbon filter first (₹200-₹400). If output TDS >80 ppm: Membrane is definitely failed, needs replacement (₹1,500-₹4,000). If output TDS 50-80 ppm: Membrane is aging but might last 6-12 more months. Calculate rejection rate: if <85%, replace membrane soon; if >85%, try replacing post-carbon first. Step 2 - Taste profile: Salty taste = membrane issue (high TDS passing through). Bitter/flat taste = post-carbon exhausted (taste/odor not being removed). Chemical taste = post-carbon or pre-carbon exhausted. Step 3 - Age of components: Post-carbon lasts 12 months, membrane lasts 24-36 months. If post-carbon is >12 months old, replace it first regardless of TDS. If membrane is >30 months old and TDS is borderline, replace membrane proactively.
Q: Can I use cheaper compatible filters instead of original brand filters?
Answer: Yes, but with important cautions: Safe to use compatible: (1) RO membranes: Reputed universal brands like DOW Filmtec, Vontron, CSM work excellently and are much cheaper (₹1,200-₹2,000 vs ₹2,500-₹4,000 original). Ensure correct GPD rating (75 GPD or 80 GPD typically). (2) Sediment filters: Universal 10-inch sediment filters work fine (₹100-₹200). Check micron rating (5 micron standard). (3) Activated carbon filters: Universal carbon blocks work well (₹200-₹300). Ensure food-grade certification. Be careful with: (1) Proprietary cartridges: Some brands (Pureit Germkill Kit, Aquaguard Taste Guard) use unique designs - universal replacement difficult. (2) Post-carbon with mineralizer: If combined unit, finding compatible replacement harder. Never use: Super-cheap no-name filters from unknown sellers (<₹100). These can leach chemicals, plastics, and cause worse taste and health issues. Best practice: For critical components (membrane, post-carbon), use either original brand or certified universal brands (NSF certified, food-grade). For pre-filters, universal options are fine.
Q: Why does my RO water taste fine in the morning but salty by evening?
Answer: Variable taste throughout the day indicates input water quality fluctuation or TDS controller issue, not membrane failure. Causes: (1) Municipal water TDS varies: Morning water has lower TDS (direct from treatment plant), evening water has higher TDS (picked up minerals from distribution pipes, mixing with bore water). Test input TDS at different times - you'll likely see 300 ppm morning, 600 ppm evening for example. (2) TDS controller bypassing more during high-pressure hours: If your RO has TDS controller, it bypasses raw water proportionally. When inlet pressure is high (morning peak flow), controller works differently than low-pressure hours. (3) Aging membrane with variable performance: Partially damaged membrane blocks TDS inconsistently based on water temperature and pressure. Solutions: (a) Test input water TDS morning vs evening to confirm fluctuation; (b) If input TDS fluctuates wildly, consider water softener or booster tank to stabilize supply; (c) Adjust or bypass TDS controller to minimum setting; (d) If membrane is >2 years old and showing inconsistent performance, replace it proactively; (e) Install pre-filter sediment tank to buffer input water quality variations.
Q: My RO water tastes like plastic. What causes this and how to fix?
Answer: Plastic taste is usually not a filter problem - it's from storage tank or new tubing. Causes: (1) New RO system or new tank: Brand new plastic components leach plasticizers for first 2-4 weeks. This is normal and harmless but unpleasant. (2) Hot weather: Plastic tanks in direct sunlight or hot rooms (>35°C) leach more plastic taste. (3) Stagnant water: Water sitting in plastic tank for >7 days absorbs plastic taste. (4) Low-quality storage tank: Cheap, non-food-grade plastic tanks leach continuously. Solutions: (a) For new systems: Flush 5-10 full tanks of water to waste over 2 weeks. Plastic taste will gradually disappear. (b) Relocate tank: Keep storage tank in cool, shaded location. Never in direct sunlight. (c) Regular usage: Empty tank completely at least once a week. Prevents taste buildup. (d) Flush before drinking: After >3 days without use, drain 2-3 liters to waste before drinking. (e) Upgrade tank: If taste persists after 6 months, replace with better quality food-grade plastic tank (₹1,200-₹2,500). Stainless steel tanks available but expensive (₹4,000-₹8,000). (f) Activated carbon contact: Some RO systems pass water through post-carbon filter AFTER tank. If yours doesn't, consider adding inline post-carbon filter (₹300-₹600) between tank and tap.
Q: Is slightly bitter taste in RO water harmful? Or just unpleasant?
Answer: Slightly bitter taste is usually not harmful, but indicates exhausted post-carbon filter or mineralizer issue. Why bitter taste occurs: (1) Post-carbon filter saturated: Activated carbon loses effectiveness after 12 months. Can't remove all residual taste compounds, causing slightly bitter aftertaste. Not harmful, just unpleasant. (2) Alkaline mineralizer over-dosing: Some RO systems add alkaline minerals (calcium, magnesium). Old or malfunctioning mineralizer cartridge over-doses, causing chalky/bitter taste. Slightly high mineral content is harmless for most people. (3) Very low TDS (<20 ppm): Ultra-pure RO water can taste flat, slightly bitter, or "empty" because it lacks all minerals. This is normal for RO water - not harmful. Health impact: Generally NOT harmful unless accompanied by high TDS (>80 ppm) which indicates membrane failure. Bitter taste from exhausted carbon or minerals is just taste issue, not safety issue. When to worry: If bitter taste is accompanied by: High output TDS (>80 ppm), metallic taste, stomach discomfort, or visible color change - then it's serious. Otherwise it's just filter replacement time. Fix: Replace post-carbon filter (₹200-₹400). If has mineralizer, replace or disable it. Taste improves immediately.
Q: What is the ideal output TDS for RO water to taste good and be healthy?
Answer: Ideal RO output TDS: 30-50 ppm for balance of taste and mineral content. Here's the breakdown: TDS ranges and characteristics: (1) <20 ppm (Ultra-pure): Tastes very flat, "empty", slightly sweet. Too pure - lacking minerals. Safe to drink but not ideal for long-term consumption (mineral deficiency over years). Used in scientific labs. (2) 20-30 ppm (Very good): Pure, clean taste. No mineral deficiency concerns if you have balanced diet. This is what most RO systems without mineralizer produce. Good option. (3) 30-50 ppm (Optimal): Best balance. Slight mineral content for taste without saltiness. This is what TDS controllers aim for. Recommended by most health experts. (4) 50-80 ppm (Acceptable): Noticeable mineral taste, might taste slightly salty to some people. Not harmful if source is clean. Indicates TDS controller set too high or aging membrane. (5) >80 ppm (Problem): Definitely salty taste. Membrane failure. Not safe if input water has contaminants. Best practice: Aim for 30-50 ppm by adjusting TDS controller (if available) or using mineralizer cartridge. Get minerals from food, not water - don't worry about very low TDS. If concerned about mineral intake with <30 ppm RO water, take multivitamin or install remineralization cartridge (₹400-₹800).
⚠️ Disclaimer: This guide is for informational and educational purposes only. Water quality and taste issues can have multiple causes, some requiring professional water testing and diagnosis. Always use food-grade, certified replacement parts for RO systems. If you experience persistent bad taste, high TDS readings (>80 ppm), or suspect heavy metal contamination, stop drinking the water immediately and consult a water quality professional. DIY filter replacement is generally safe for post-carbon and pre-filters, but RO membrane replacement should be done by trained technicians. The author and website are not responsible for any health issues, water contamination, or equipment damage resulting from DIY repairs or use of non-certified replacement parts. When in doubt, always prioritize safety and professional service over cost savings.
Important Safety Reminder
If you're not comfortable with any step, or if the problem persists after trying these solutions, please contact a qualified technician. Safety should always be your first priority when dealing with electrical appliances.
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Oil-filled heaters save ₹500-₹1,200/winter through heat retention vs fan heaters (quick 5-min warmup). Compare silence (0 dB vs 50 dB), safety for kids, running costs @₹8/kWh for Delhi-NCR, Punjab, Haryana winters.
Vertical vs Horizontal Geyser 2025: Which Gives Better Hot Water? (Space Guide)
Vertical geysers give 15-20% more consistent hot water vs horizontal. Compare space needs (18"×14" vs 24"×10"), installation cost (₹500-800 difference), thermal efficiency & real Indian bathroom fits.
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