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RO Water Purifiers

None of these 10 makes it 100% safe

The quality of drinking water is very important for human health – and today this is truer than ever before. Truer because not only are our water reserves depleting and getting polluted, but also access to safe water is unequal. The water we receive from rivers/underground reserves is polluted with heavy metals, bacteria and pathogenic organisms. (It is reported that groundwater in one-third of India’s 600 districts is not fit for drinking as the concentration of fluoride, iron, salinity and arsenic exceeds the tolerance levels.) Some of us boil the water before drinking it; some of us buy packaged water regularly; some of us invest in water filters and purifiers. The last mentioned is a relatively expensive proposition but consumers are going for it because it is considered to be the best bet against unsafe or contaminated water. As of today, the market for reverse osmosis (RO) water purifiers is growing tremendously and various brands are available in this category. At the same time, even as water filters/purifiers with latest technologies – reverse osmosis and ultraviolet (UV) – have been developed, conformation to guidelines and standards is not equal. These new, advanced units have improved the quality of water, but is their potability in sync with Indian Standard or WHO guidelines? Do we, as consumers, know what impurities is a water purifier supposed to eliminate? Do we even know what these impurities are, not counting the usual suspects like bacteria and heavy metals?

Getting straight to the point, none of the 10 brands we tested could completely remove E. coli, that dreaded source of gastrointestinal illness. E. coli normally inhabits the stomach and intestines and can be consumed in contaminated water, milk, or food, or is transmitted through the bite of a fly or other insect.

Similarly, none of the 10 brands met the requirements of Indian Standard during the test for MS2 virus removal. On the basis of these two findings, it may be concluded that none of the tested brands can assure us of 100 per cent safe water.

Further, the level of removal of copper in most of the brands was below the specified requirement. In some brands, the level of arsenic removal was also below the specified IS requirement.

Some more non-compliances were observed in the qualitative tests we carried out: for example, in declared storage capacity we found deviation by as much as 29 per cent. The brands we tested were found with waste water in the range of 62 per cent to 71 per cent.

So, are consumers getting real value for their money, especially since water purifiers come at a relatively steep cost? The following report touches upon all critical functions that a water purifier, specifically the RO type, is expected to deliver.

The test programme developed by the Consumer Voice team is in accordance with IS: 16240: 2015. Ten brands of RO water purifiers were tested in an NABLaccredited laboratory for comparative assessment. It may be noted that the quality of RO water that consumers get at the initial period after installation and after a certain period are critical determinants of safety, and so is the consistency of the water purifier system.

Do You Need It At All?

  • RO systems are useful where the TDS levels are above 1,000 mg/litre and hardness is on the higher side. If the municipal water supply is quite satisfactory and has permissible TDS levels, RO purifiers are not required – UV purifiers should be used instead.
  • So, get your water tested. A water test will specify many factors. It will also help you make a decision based on facts and figures. For example, if the water has a very high amount of magnesium, fluoride, nitrates or calcium salts, RO purifier will be the best for you.
  • If the water supplied at your location is highly contaminated (with microbes, bacteria and virus) and is dirty as well, RO/UF + UV purifiers are the best solution. The UV rays destroy the microbes and the RO/UF filters out their dead bodies and other contaminants.

RO vs UV vs UF

RO Water Purifier UV Water Purifier UF (Ultrafiltration) Water Purifier
Requires electricity to work Requires electricity to work Does not need electricity
Blocks and removes all germs and viruses from purified water Kills all germs including viruses, but their bodies remain in the water Removes germs and viruses from purified water
Requires electricity to boost tapwater pressure Can work with normal tapwater pressure Will function with normal tapwater pressure
Removes dissolved salts Cannot remove dissolved salts Cannot remove dissolved salts
Has prefiltration to work with dirty water Water must be clear for UV to work Works with muddy, dirty turbid water

Key Findings

  • Based on the overall score, Aquaguard and Kent are the top performers
  • Some of the water purifiers could not meet the specified limit for toxic metals like arsenic, mercury and copper.
  • None of the brands could meet the requirements for microbiological safety, specifically with regards to E.coli and MS2 virus. Thus, none can be said to provide water that is completely safe for consumption
  • Storage capacity of Aquaguard, Pureit, Usha, Electrolux and Tata Swach was found to be less than their claim.
  • Waste water of all tested brands was found between 62% and 71%, which was within the prescribed limit.
  • Total dissolved solids(TDS) reduction level was within the requirements set by Indian Standard. Some brands - AO Smith, LG, Pureit, Whirlpool, Zero B and Electrolux - reduced the TDS to less than 100, which is not desirable because intake of required essential minerals also gets reduced in the process.

Tests Performed

  1. For Physiochemical Parameters
  2. For Microbiological Activity
  3. For Toxic Metals/Materials
  4. For General Qualities

You can see list of our CV Comparative Tests- RO Water Purifiers below, perform Side-by-Side comparison. If you need further help, do have a look at Conzumr Guides and Tips. Alternatively you can view all Water Purifier to choose your own favourites.


Reverse osmosis is the key principle behind RO water purifiers. Water from higher TDS (total dissolved solids) level – that is, very hard water – is transferred to the lower TDS level through a filtering membrane. RO technology uses high pressure to push water through an extremely fine filter or membrane. The holes in this membrane are as small as .0001 microns. They remove dissolved salts along with pollutants and other physical contaminants including virus, and harmful metals, minerals, bacteria and microorganisms. Most of the RO purifiers also comprise of TDS controllers (to adjust the TDS level). The filter is kept clean by flushing the separated contaminants so they drain away.

In the quest to live healthier lives, many people have turned to water filters. Some water filters fit into pitchers to provide clean drinking water. Some filters attach to faucets and filter water as it flows out of the tap, and still others filter water as it enters a house so that all of the water in the home is filtered.


Side by Side comparison

Alt Model #
Aquaguard Enhance RO, UV : Aquaguard Enhance RO + UV
PRIDE : Kent Pride 8 Litres (RO + UF)
Minerala 90 Platinum : 
WAW35RW2RP : 
A. O. Smith Puritee Plus : A. O. Smith Puritee +
Platina Silver RO : Platina Silver RO + UV
Wave : 
ROS 1375 : 
Pureit Marvella RO : 
1095 : 
Series #
Aquaguard Enhance RO, UV : Aquaguard Enhance
PRIDE : Pride
Minerala 90 Platinum : Minerala
WAW35RW2RP : WAW
A. O. Smith Puritee Plus : 
Platina Silver RO : 
Wave : 
ROS 1375 : 
Pureit Marvella RO : Marvella
1095 : 
Aquaguard Enhance RO, UV
Minerala 90 Platinum
WAW35RW2RP
A. O. Smith Puritee Plus
Platina Silver RO
Pureit Marvella RO
Buy Now Wave
SnapDeal ₹ 12608 18% off
Amazon.in ₹ 12639 17% off
Zero B ₹ 15295
Refreshed 18 hours ago
Buy Now ROS 1375
Usha ₹ 13990
Refreshed 2 years ago
Buy Now 1095
Elecrtolux ₹ 18000
Refreshed 2 years ago
Highlights
Installation
Aquaguard Enhance RO, UV : Counter-Top, Wall Mounted
PRIDE : Wall Mounted
Minerala 90 Platinum : Wall Mounted
WAW35RW2RP : Wall Mounted
A. O. Smith Puritee Plus : Counter-Top
Platina Silver RO : Wall Mounted
Wave : Wall Mounted
ROS 1375 : Wall Mounted
Pureit Marvella RO : Counter-Top, Wall Mounted
1095 : Wall Mounted
Total Score out of 100
Aquaguard Enhance RO, UV : 73
PRIDE : 73
Minerala 90 Platinum : 72
WAW35RW2RP : 72
A. O. Smith Puritee Plus : 71
Platina Silver RO : 70
Wave : 70
ROS 1375 : 70
Pureit Marvella RO : 70
1095 : 70
Purification Capacity Per Hour
Aquaguard Enhance RO, UV : 15 Ltr/hr
PRIDE : 15 Ltr/hr
Minerala 90 Platinum : 13.5 Ltr/hr
WAW35RW2RP : -
A. O. Smith Puritee Plus : 15 Ltr/hr
Platina Silver RO : -
Wave : -
ROS 1375 : -
Pureit Marvella RO : 12 Ltr/hr
1095 : -
MRP (Rs)
Aquaguard Enhance RO, UV : 13999
PRIDE : 16500
Minerala 90 Platinum : 17490
WAW35RW2RP : 21990
A. O. Smith Puritee Plus : 16750
Platina Silver RO : 13999
Wave : 15295
ROS 1375 : 13990
Pureit Marvella RO : 16000
1095 : 18000
Aquaguard Enhance RO, UV : UV+RO
PRIDE : RO+UF
Minerala 90 Platinum : RO
WAW35RW2RP : RO
A. O. Smith Puritee Plus : RO + SCMT
Platina Silver RO : RO
Wave : RO
ROS 1375 : RO
Pureit Marvella RO : RO
1095 : RO
UV+RO: Ultra Violet & Reverse Osmosis
RO+UF: Reverse Osmosis & Ultra Filtration
RO: Reverse Osmosis
RO + SCMT: Silver chraged membrane technology
RO: Reverse Osmosis
Power Consumption
Aquaguard Enhance RO, UV : 35 W
PRIDE : 60 W
Minerala 90 Platinum : 35 W
WAW35RW2RP : 32 W
A. O. Smith Puritee Plus : 48 W
Platina Silver RO : 24 W
Wave : 24 W
ROS 1375 : 30 W
Pureit Marvella RO : 36 W
1095 : 60 W
Storage
Aquaguard Enhance RO, UV : 
PRIDE : 
Minerala 90 Platinum : 
WAW35RW2RP : 
A. O. Smith Puritee Plus : 
Platina Silver RO : 
Wave : 
ROS 1375 : 
Pureit Marvella RO : 
1095 : 
Tank Capacity
Aquaguard Enhance RO, UV : 7 L
PRIDE : 8 L
Minerala 90 Platinum : 8.5 L
WAW35RW2RP : 8 L
A. O. Smith Puritee Plus : 9 L
Platina Silver RO : 7 L
Wave : -
ROS 1375 : -
Pureit Marvella RO : 10 L
1095 : -
Manufactured/Marketed by
Aquaguard Enhance RO, UV : Eureka Forbes Ltd
PRIDE : Kent R-O System Ltd
Minerala 90 Platinum : Whirlpool of India Ltd
WAW35RW2RP : LG Electronics Pvt. Ltd
A. O. Smith Puritee Plus : A.O Smith India Water Products Pvt. Ltd
Platina Silver RO : Tata Chemicals Ltd
Wave : ION Exchange (I) Ltd
ROS 1375 : Usha Shriram Enterprises Pvt. Ltd
Pureit Marvella RO : Hindustan Unilever Ltd
1095 : Electrolux Purifiers
Electric
Aquaguard Enhance RO, UV : Electric
PRIDE : Electric
Minerala 90 Platinum : Electric
WAW35RW2RP : Electric
A. O. Smith Puritee Plus : Electric
Platina Silver RO : Electric
Wave : Electric
ROS 1375 : Electric
Pureit Marvella RO : Electric
1095 : Electric
Warranty(Months)
Aquaguard Enhance RO, UV : 12
PRIDE : 12
Minerala 90 Platinum : 12
WAW35RW2RP : 12
A. O. Smith Puritee Plus : 24
Platina Silver RO : 12
Wave : 12
ROS 1375 : 12
Pureit Marvella RO : 12
1095 : 12
Design
TDS Controller
Aquaguard Enhance RO, UV : 
PRIDE : 
Minerala 90 Platinum : -
WAW35RW2RP : -
A. O. Smith Puritee Plus : 
Platina Silver RO : -
Wave : -
ROS 1375 : -
Pureit Marvella RO : -
1095 : -
Number of Purification Stages
Aquaguard Enhance RO, UV : 5
PRIDE : 5
Minerala 90 Platinum : 6
WAW35RW2RP : 5
A. O. Smith Puritee Plus : 7
Platina Silver RO : 5
Wave : -
ROS 1375 : -
Pureit Marvella RO : 6
1095 : -
Colour
Aquaguard Enhance RO, UV : White with Black
PRIDE : White
Minerala 90 Platinum : Silver
WAW35RW2RP : White
A. O. Smith Puritee Plus : White and Red
Platina Silver RO : White
Wave : White
ROS 1375 : White
Pureit Marvella RO : Silver
1095 : White
Material of Body
Aquaguard Enhance RO, UV : ABS Plastic
PRIDE : Food grade, non-toxic, engineering grade plastic
Minerala 90 Platinum : -
WAW35RW2RP : -
A. O. Smith Puritee Plus : -
Platina Silver RO : ABS Plastic
Wave : -
ROS 1375 : -
Pureit Marvella RO : Food grade, non-toxic, engineering grade plastic
1095 : -
Brands Tested
Rank
Aquaguard Enhance RO, UV : 1
PRIDE : 1
Minerala 90 Platinum : 2
WAW35RW2RP : 2
A. O. Smith Puritee Plus : 3
Platina Silver RO : 4
Wave : 4
ROS 1375 : 4
Pureit Marvella RO : 4
1095 : 4
General Specification
UV Lamp Power
Aquaguard Enhance RO, UV : 11 W
PRIDE : 0.01 W
Minerala 90 Platinum : -
WAW35RW2RP : -
A. O. Smith Puritee Plus : -
Platina Silver RO : -
Wave : -
ROS 1375 : -
Pureit Marvella RO : -
1095 : -
Input Water Pressure (kg/cm2)
Aquaguard Enhance RO, UV : 2
PRIDE : 0.3
Minerala 90 Platinum : -
WAW35RW2RP : -
A. O. Smith Puritee Plus : -
Platina Silver RO : -
Wave : -
ROS 1375 : -
Pureit Marvella RO : 0.35 - 2.11
1095 : -
Input Water Temperature
Aquaguard Enhance RO, UV : 10-40 °C
PRIDE : 35 °C
Minerala 90 Platinum : -
WAW35RW2RP : Room Temperature °C
A. O. Smith Puritee Plus : 5°C to 45°C °C
Platina Silver RO : -
Wave : -
ROS 1375 : -
Pureit Marvella RO : -
1095 : -
Other Features
Aquaguard Enhance RO, UV : Unique E-boiling Technology - Automatic Water Level Sensor - Silver Surety Technology - Dual Flow Tap - Electronic Membrane Life Enhancer EMLE
PRIDE : UF after RO ensures enhanced water - Patented TDS Control - Spin-welded RO Membrane
Minerala 90 Platinum : -
WAW35RW2RP : -
A. O. Smith Puritee Plus : -
Platina Silver RO : -
Wave : -
ROS 1375 : -
Pureit Marvella RO : -
1095 : -
Applicable TDS Range in Input Water
Aquaguard Enhance RO, UV : 500 - 1500 mg/litre
PRIDE : -
Minerala 90 Platinum : -
WAW35RW2RP : -
A. O. Smith Puritee Plus : -
Platina Silver RO : -
Wave : -
ROS 1375 : -
Pureit Marvella RO : -
1095 : -
Max Input water chlorine
Aquaguard Enhance RO, UV : 2ppm (max.)
PRIDE : -
Minerala 90 Platinum : -
WAW35RW2RP : -
A. O. Smith Puritee Plus : -
Platina Silver RO : -
Wave : -
ROS 1375 : -
Pureit Marvella RO : -
1095 : -
Input Water Turbidity
Aquaguard Enhance RO, UV : 15
PRIDE : -
Minerala 90 Platinum : -
WAW35RW2RP : -
A. O. Smith Puritee Plus : -
Platina Silver RO : -
Wave : -
ROS 1375 : -
Pureit Marvella RO : 10 NTU
1095 : -
Input Water Iron content ( Max)
Aquaguard Enhance RO, UV : 0.3 mg/lit. (max)
PRIDE : -
Minerala 90 Platinum : -
WAW35RW2RP : -
A. O. Smith Puritee Plus : -
Platina Silver RO : -
Wave : -
ROS 1375 : -
Pureit Marvella RO : 0.3 mg/lit. (max)
1095 : -
Maximum Duty Cycle
Aquaguard Enhance RO, UV : -
PRIDE : 75 litres/day
Minerala 90 Platinum : -
WAW35RW2RP : -
A. O. Smith Puritee Plus : -
Platina Silver RO : -
Wave : -
ROS 1375 : -
Pureit Marvella RO : -
1095 : -
Purification
Aquaguard Enhance RO, UV : Universal
PRIDE : -
Minerala 90 Platinum : -
WAW35RW2RP : -
A. O. Smith Puritee Plus : Low TDS (Rivers, Lakes)
Platina Silver RO : -
Wave : -
ROS 1375 : -
Pureit Marvella RO : -
1095 : -
Low TDS (Rivers, Lakes): Water from rivers & lakes having low TDS, which does not taste salty. Municipal/Corporation/Sweet tasting water
Life of UV Lamp
Aquaguard Enhance RO, UV : 5000 burning hours
PRIDE : -
Minerala 90 Platinum : -
WAW35RW2RP : -
A. O. Smith Puritee Plus : -
Platina Silver RO : -
Wave : -
ROS 1375 : -
Pureit Marvella RO : -
1095 : -
Aquaguard Enhance RO, UV : Chemi block, EMLE, I-Filter, RO Membrane, Silver Impregnated Post Carbon, Taste Enhancer Cartridge
PRIDE : Carbon Block, Sediment Filter, Silver Impregnated Post Carbon, UF
Minerala 90 Platinum : Pre-Filter
WAW35RW2RP : Post Carbon, Pre carbon, Sediment Filter
A. O. Smith Puritee Plus : Pre carbon, Sediment Filter
Platina Silver RO : -
Wave : -
ROS 1375 : -
Pureit Marvella RO : Activated Carbon, PP Melt Brown, RO Membrane, Ultra ventilated membrane
1095 : -
EMLE: Prevents scaling of dissolved salts on the surface of the membrane and hence enhance both membrane life and performance.
RO Membrane: Unique RO technology membrane removes excess TDS, blocks dissolved impurities and chemical contaminants, while retaining essential minerals in the drinking water. It also helps removing dissolved salts, hardness, pesticides and heavy metals like arsenic, lead and mercury.
RO Membrane: Unique RO technology membrane removes excess TDS, blocks dissolved impurities and chemical contaminants, while retaining essential minerals in the drinking water. It also helps removing dissolved salts, hardness, pesticides and heavy metals like arsenic, lead and mercury.
Pre-Filter Purification
Aquaguard Enhance RO, UV : 
PRIDE : 
Minerala 90 Platinum : 
WAW35RW2RP : -
A. O. Smith Puritee Plus : -
Platina Silver RO : -
Wave : -
ROS 1375 : -
Pureit Marvella RO : -
1095 : -
TDS Reduction
Aquaguard Enhance RO, UV : 90 % (approx)
PRIDE : -
Minerala 90 Platinum : 93
WAW35RW2RP : -
A. O. Smith Puritee Plus : > 95 percent
Platina Silver RO : -
Wave : -
ROS 1375 : -
Pureit Marvella RO : 90 % (approx)
1095 : -
% Water Recovery
Aquaguard Enhance RO, UV : 25% approx in RO Mode
PRIDE : -
Minerala 90 Platinum : 25
WAW35RW2RP : -
A. O. Smith Puritee Plus : 30
Platina Silver RO : -
Wave : -
ROS 1375 : -
Pureit Marvella RO : -
1095 : -
Membrane Type
Aquaguard Enhance RO, UV : Thin Film Composite RO
PRIDE : Thin Film Composite RO
Minerala 90 Platinum : -
WAW35RW2RP : -
A. O. Smith Puritee Plus : Side Stream RO membrane
Platina Silver RO : -
Wave : -
ROS 1375 : -
Pureit Marvella RO : Thin film composite spiral wound
1095 : -
Weight and Dimensions
Net Weight
Aquaguard Enhance RO, UV : 8.2 kg
PRIDE : 9 kg
Minerala 90 Platinum : 10 kg
WAW35RW2RP : 11 kg
A. O. Smith Puritee Plus : 9.3 kg
Platina Silver RO : 10.5 kg
Wave : -
ROS 1375 : -
Pureit Marvella RO : 8.4 kg
1095 : -
Width
Aquaguard Enhance RO, UV : 316 mm
PRIDE : 255 mm
Minerala 90 Platinum : 534 mm
WAW35RW2RP : 365 mm
A. O. Smith Puritee Plus : 310 mm
Platina Silver RO : 420 mm
Wave : -
ROS 1375 : -
Pureit Marvella RO : 360 mm
1095 : -
Depth
Aquaguard Enhance RO, UV : 251 mm
PRIDE : 410 mm
Minerala 90 Platinum : 412 mm
WAW35RW2RP : 270 mm
A. O. Smith Puritee Plus : 305 mm
Platina Silver RO : 168 mm
Wave : -
ROS 1375 : -
Pureit Marvella RO : 265 mm
1095 : -
Height
Aquaguard Enhance RO, UV : 462 mm
PRIDE : 515 mm
Minerala 90 Platinum : -
WAW35RW2RP : 500 mm
A. O. Smith Puritee Plus : 490 mm
Platina Silver RO : 537 mm
Wave : -
ROS 1375 : -
Pureit Marvella RO : 480 mm
1095 : -
Power
Rated Voltage
Aquaguard Enhance RO, UV : -
PRIDE : -
Minerala 90 Platinum : 230 V
WAW35RW2RP : -
A. O. Smith Puritee Plus : -
Platina Silver RO : -
Wave : -
ROS 1375 : -
Pureit Marvella RO : -
1095 : -
Input Voltage
Aquaguard Enhance RO, UV : 230VAC/ 50-60 Hz
PRIDE : 100-300 V AC/50-60 Hz
Minerala 90 Platinum : 160 - 270 VAC
WAW35RW2RP : -
A. O. Smith Puritee Plus : 150 – 300 VAC/ 50 Hz
Platina Silver RO : -
Wave : -
ROS 1375 : -
Pureit Marvella RO : 100-240VAC/ 50-60 Hz
1095 : -
Watts Combination Per Month
Aquaguard Enhance RO, UV : -
PRIDE : -
Minerala 90 Platinum : -
WAW35RW2RP : 30 kW
A. O. Smith Puritee Plus : -
Platina Silver RO : -
Wave : -
ROS 1375 : -
Pureit Marvella RO : -
1095 : -
Booster Pump Voltage
Aquaguard Enhance RO, UV : 24 V
PRIDE : 24 V
Minerala 90 Platinum : -
WAW35RW2RP : -
A. O. Smith Puritee Plus : -
Platina Silver RO : -
Wave : -
ROS 1375 : -
Pureit Marvella RO : 24 V
1095 : -

The Bureau of Indian Standards (BIS) has specified requirements for removal/reduction ofheavy metals in IS:16240. We tested the 10 brands for presence of the following heavy metals:

Arsenic: As many as six brands – Tata Swach, Zero B, Kent, Aquaguard, Electrolux and Usha – did not meet the requirement (a maximum 0.01 mg/l).

Copper: None of the brands met the requirement set by Indian Standard (0.05 mg/l).

Mercuy: All the brands more or less met the specified requirement – minor deviations were observed in Pureit, Aquaguard and Usha.

Cadmium: Minor deviation was observed in one brand, Pureit. All other brands met the standard requirement.

Iron: All the brands met the requirements, with the exception of deviation in two brands, Whirlpool and Usha.

Lead and chromium: All brands met the requirements.

Score out of 14 (for all toxic metals)
Aquaguard Enhance RO, UV : 12.15
PRIDE : 11.85
Minerala 90 Platinum : 12.52
WAW35RW2RP : 13.55
A. O. Smith Puritee Plus : 12.48
Platina Silver RO : 11.75
Wave : 11.85
ROS 1375 : 12.34
Pureit Marvella RO : 12.1
1095 : 12.03
Physicochemical Parameters
Aquaguard Enhance RO, UV : 5.74
PRIDE : 4.8
Minerala 90 Platinum : 4.72
WAW35RW2RP : 4.63
A. O. Smith Puritee Plus : 3.91
Platina Silver RO : 5.88
Wave : 4.62
ROS 1375 : 4.92
Pureit Marvella RO : 4.34
1095 : 4.63
Total dissolved solids (TDS) refer to the combined content of all inorganic and organic substance contained in a liquid; these are present in a molecular, iodised, or micro-granular suspended form. RO systems are specifically designed to effectively remove TDS to a great extent. Where the TDS level of supply/ground water is high, from 1,000 up to 2,500–3,000, it is recommended that RO systems be installed for drinking-water purpose. A special cellulose membrane cartridge plays a key role in removing TDS from the input water.

As per Indian Standard, an RO system shall reduce TDS level of feed water to less than or equal to 500 mg/l.

  • Al brands reduced the TDS to below the limit specified (500 mg/l) when the input level was maintained at a fixed level.
  • Tata Swach scored highest on this parameter, followed by Aquaguard.
  • Some brands reduced the TDS level to below 100, which is also not desirable due to their reducing the intake level of essential minerals.

Aquaguard Enhance RO, UV : 3.92
PRIDE : 4
Minerala 90 Platinum : 4
WAW35RW2RP : 4
A. O. Smith Puritee Plus : 3.84
Platina Silver RO : 4
Wave : 3.84
ROS 1375 : 3.68
Pureit Marvella RO : 3.92
1095 : 3.76
This refers to the amount of dissolved solid particles that are suspended in the water and that cause light rays shining through the water to scatter. Thus, turbidity makes the water cloudy or even opaque in extreme cases.

The turbidity of drinking water should not be more than 5 NTU and ideally be below 1 NTU. This is a key quality indicator for a water filter/purifier.

  • All the brands were able to remove turbidity to a level that makes it safe and suitable for drinking.
  • Kent, Whirlpool, LG and Tata Swach could remove 100 per cent turbidity and scored highest on this parameter.
Aquaguard Enhance RO, UV : 3.28
PRIDE : 3.09
Minerala 90 Platinum : 3.6
WAW35RW2RP : 3.18
A. O. Smith Puritee Plus : 3.28
Platina Silver RO : 3.15
Wave : 3.6
ROS 1375 : 3.84
Pureit Marvella RO : 3.36
1095 : 3.04
As per Indian Standard, the minimum recovery of product water shall be equal to or more than 20 per cent. So, waste water should not be more than 80%.
  • Waste water was in the range of 62 per cent–71.4 per cent. This means the recovery of water in all brands was well above the prescribed limit of 20%.

RO and RO+UV water purifiers produce a lot of waste water during the purification process. Thus, if you pass four litres of water through an RO purifier, it will produce just about one litre of potable water. All the impurities are concentrated in the waste water and hence it is not drinkable.

Can the Waste Be Used?

a) First thing: test the TDS in the waste-water stream. If the TDS is below 1,000, you can use the water in your plants.

b) Alternately, mix some of that water with tap water to mop the house. Make sure you dilute it with tap water because if the TDS is high and you use just the RO waste to mop the floor, you may see some salt deposition after the water dries.

c) You can use the waste water to clean the sewage pipe at home or kitchen because of its saline nature..

d) You can use it to flush toilets.

Aquaguard Enhance RO, UV : 4
PRIDE : 4
Minerala 90 Platinum : 4
WAW35RW2RP : 4
A. O. Smith Puritee Plus : 4
Platina Silver RO : 4
Wave : 4
ROS 1375 : 4
Pureit Marvella RO : 4
1095 : 4
Taste and odour of output water should be acceptable; in other words, there should not be any bad odour or taste.

All the brands gave output water with agreeable taste and odour.

Aquaguard Enhance RO, UV : 2.77
PRIDE : 2.87
Minerala 90 Platinum : 2.95
WAW35RW2RP : 2.65
A. O. Smith Puritee Plus : 2.75
Platina Silver RO : 2.54
Wave : 2.56
ROS 1375 : 2.77
Pureit Marvella RO : 2.37
1095 : 2.81

pH is a measure of the acidity or alkalinity of a solution. Aqueous solutions at 25 degrees C with a pH less than 7 are considered to be acidic, while those with a pH greater than 7 are considered to be basic (alkaline). When pH level is 7.0, it is defined as neutral at 25 degrees C.

As per Indian Standard, the pH of drinking water shall be 6.5 to 8.5.

Four brands – LG, Pureit, Zero B and Tata Swach – showed slight deviation from the pH requirement for drinking water.

Aquaguard Enhance RO, UV : 2.95
PRIDE : 2.97
Minerala 90 Platinum : 2.9
WAW35RW2RP : 2.98
A. O. Smith Puritee Plus : 2.97
Platina Silver RO : 2.98
Wave : 2.9
ROS 1375 : 2.72
Pureit Marvella RO : 2.98
1095 : 2.95
Water hardness denotes the presence of chloride and sulphates of calcium and magnesium salts in water. It is usually expressed in milligrams per litre of dissolved calcium and magnesium carbonate. Calcium and magnesium enter water mainly through the weathering of rocks. The more calcium and magnesium in water, the harder the water.
  • The lowest percentages of hardness reduction were found in Usha (96.88), Zero B (98.89) and Whirlpool (98.89).
  • All other brands reduced hardness by more than 99 per cent
  • Aquaguard Enhance RO, UV : 2
    PRIDE : 2
    Minerala 90 Platinum : 2
    WAW35RW2RP : 2
    A. O. Smith Puritee Plus : 2
    Platina Silver RO : 2
    Wave : 2
    ROS 1375 : 2
    Pureit Marvella RO : 2
    1095 : 2
    The presence of residual chlorine in drinking water indicates that a sufficient amount of chlorine added initially to the water to inactivate bacteria and certain viruses that cause diarrhoea, as well as to ensure that the water is protected from recontamination. Residues of chlorine must be absent in the output water of water purifiers. This test was conducted after all other tests.
    • All the brands were able to reduce 100 per cent residual chlorine.

    The presence of bacteria and pathogenic (disease causing) organisms is a concern when considering the safety of drinking water. Pathogenic organisms can cause intestinal infections, dysentery, hepatitis, typhoid fever, cholera and other illnesses. As per the BIS requirement, the RO purifier shall inactivate/kill the selected standard challenging organism E. coli.

    Aquaguard Enhance RO, UV : 99.7
    PRIDE : 99.6
    Minerala 90 Platinum : 99.6
    WAW35RW2RP : 99.6
    A. O. Smith Puritee Plus : 99.9
    Platina Silver RO : 99.6
    Wave : 99.4
    ROS 1375 : 99.6
    Pureit Marvella RO : 99.6
    1095 : 99.5

    When E. coli exceeds the permissible level in water, consumers are advised to boil the water they use for cooking and drinking, and even for brushing teeth. As per Indian Standard, the requirement is 99.9999 percentage reduction in E. coli. We observed all tested brands for four consecutive weeks to check percantage reduction in E. coli levels.

  • None of the brands we tested.met the requirements of Indian Standard for E. coli reduction. Hence, none of these RO water filters can be said to be completely safe for drinking.
  • Aquaguard Enhance RO, UV : 99.5 %
    PRIDE : 98.5 %
    Minerala 90 Platinum : 99.5 %
    WAW35RW2RP : 98.8 %
    A. O. Smith Puritee Plus : 99.6 %
    Platina Silver RO : 99.5 %
    Wave : 98.5 %
    ROS 1375 : 95.6 %
    Pureit Marvella RO : 98.8 %
    1095 : 96.3 %

    When E. coli exceeds the permissible level in water, consumers are advised to boil the water they use for cooking and drinking, and even for brushing teeth. As per Indian Standard, the requirement is 99.9999 percentage reduction in E. coli. We observed all tested brands for four consecutive weeks to check percantage reduction in E. coli levels.

  • None of the brands we tested.met the requirements of Indian Standard for E. coli reduction. Hence, none of these RO water filters can be said to be completely safe for drinking.
  • E. coli Score out of 16
    Aquaguard Enhance RO, UV : 4.32
    PRIDE : 4.28
    Minerala 90 Platinum : 4.28
    WAW35RW2RP : 3.96
    A. O. Smith Puritee Plus : 4.44
    Platina Silver RO : 4.2
    Wave : 3.68
    ROS 1375 : 3.16
    Pureit Marvella RO : 4
    1095 : 3.12
    Aquaguard Enhance RO, UV : 99.7 cfu/100ml
    PRIDE : 99.6 cfu/100ml
    Minerala 90 Platinum : 99.6 cfu/100ml
    WAW35RW2RP : 99.4 cfu/100ml
    A. O. Smith Puritee Plus : 99.5 cfu/100ml
    Platina Silver RO : 99.5 cfu/100ml
    Wave : 99.5 cfu/100ml
    ROS 1375 : 99.4 cfu/100ml
    Pureit Marvella RO : 99.5 cfu/100ml
    1095 : 99.5 cfu/100ml

    A microorganism smaller than bacteria, the MS2 virus cannot grow or reproduce apart from in a living cell. Viruses are the smallest agents of disease, and perhaps the most problematic, because they are as minute as 0.04 u (micron). Viruses cause many common human infections and are also responsible for a bevy of rare diseases. Viruses can infect all types of life forms, from animals and plants to bacteria and archaea.

    Based on the requirement specified by IS: 16240,MS2 virus was spiked in input water and the output sample was tested to check the virus-removal efficiency of purifiers.

    • None of the brands we tested met the requirement of Indian Standard for removal of MS2 virus. Hence, none of these RO water filters can be said to be completely safe for drinking.
    Aquaguard Enhance RO, UV : 99.4 cfu/100ml
    PRIDE : 93.4 cfu/100ml
    Minerala 90 Platinum : 93.3 cfu/100ml
    WAW35RW2RP : 93.6 cfu/100ml
    A. O. Smith Puritee Plus : 93.4 cfu/100ml
    Platina Silver RO : 97.3 cfu/100ml
    Wave : 96 cfu/100ml
    ROS 1375 : 93.7 cfu/100ml
    Pureit Marvella RO : 96.3 cfu/100ml
    1095 : 93.8 cfu/100ml

    A microorganism smaller than bacteria, the MS2 virus cannot grow or reproduce apart from in a living cell. Viruses are the smallest agents of disease, and perhaps the most problematic, because they are as minute as 0.04 u (micron). Viruses cause many common human infections and are also responsible for a bevy of rare diseases. Viruses can infect all types of life forms, from animals and plants to bacteria and archaea.

    Based on the requirement specified by IS: 16240,MS2 virus was spiked in input water and the output sample was tested to check the virus-removal efficiency of purifiers.

    • None of the brands we tested met the requirement of Indian Standard for removal of MS2 virus. Hence, none of these RO water filters can be said to be completely safe for drinking.
    MS2 Virus Score out of 16
    Aquaguard Enhance RO, UV : 5.68
    PRIDE : 5.68
    Minerala 90 Platinum : 4.16
    WAW35RW2RP : 4.08
    A. O. Smith Puritee Plus : 4.2
    Platina Silver RO : 4.2
    Wave : 4.12
    ROS 1375 : 4.08
    Pureit Marvella RO : 4.12
    1095 : 4.2
    Aquaguard Enhance RO, UV : Able to reduce the pesticide residues
    PRIDE : Able to reduce the pesticide residues
    Minerala 90 Platinum : Able to reduce the pesticide residues
    WAW35RW2RP : Able to reduce the pesticide residues
    A. O. Smith Puritee Plus : Able to reduce the pesticide residues
    Platina Silver RO : Able to reduce the pesticide residues
    Wave : Able to reduce the pesticide residues
    ROS 1375 : Able to reduce the pesticide residues
    Pureit Marvella RO : Able to reduce the pesticide residues
    1095 : Able to reduce the pesticide residues
    • In India, high concentrations of both organochlorine and organophosphorous pesticides have been found in surface and ground water samples. Reverse-osmosis water filters are expected to remove pesticide residues.
    • We tested the 10 brands for pesticide residues. They were all able to reduce the pesticide residues and scored equally well.
    General Qualities
    Aquaguard Enhance RO, UV : 3.2
    PRIDE : 4
    Minerala 90 Platinum : 3.52
    WAW35RW2RP : 3.76
    A. O. Smith Puritee Plus : 4
    Platina Silver RO : 2.86
    Wave : 4
    ROS 1375 : 3.14
    Pureit Marvella RO : 3.2
    1095 : 3.14
    Water-storage capacity should be as declared by the manufacturer.
    • In five brands – Tata Swach, Electrolux, Usha, Aquaguard and Pureit – the water-storage capacity was found to be less than the declared.
    Aquaguard Enhance RO, UV : 5
    PRIDE : 5
    Minerala 90 Platinum : 5
    WAW35RW2RP : 5
    A. O. Smith Puritee Plus : 5
    Platina Silver RO : 5
    Wave : 5
    ROS 1375 : 5
    Pureit Marvella RO : 5
    1095 : 5
    All the brands scored equally well.
    Aquaguard Enhance RO, UV : 3
    PRIDE : 3
    Minerala 90 Platinum : 2.7
    WAW35RW2RP : 1.95
    A. O. Smith Puritee Plus : 2.4
    Platina Silver RO : 1.8
    Wave : 2.1
    ROS 1375 : 2.4
    Pureit Marvella RO : 2.4
    1095 : 2.25
    It is the quantity of output water released from the system in a particular time period. Production rate should not be less than five litres per hour.
    Aquaguard Enhance RO, UV : 3.6
    PRIDE : 3.4
    Minerala 90 Platinum : 3.6
    WAW35RW2RP : 3.8
    A. O. Smith Puritee Plus : 3.8
    Platina Silver RO : 3.6
    Wave : 3.4
    ROS 1375 : 3.4
    Pureit Marvella RO : 3.4
    1095 : 4
    Overall, the workmanship and finish ranged from good to very good.
    Aquaguard Enhance RO, UV : 3
    PRIDE : 3
    Minerala 90 Platinum : 3
    WAW35RW2RP : 3
    A. O. Smith Puritee Plus : 3
    Platina Silver RO : 3
    Wave : 3
    ROS 1375 : 3
    Pureit Marvella RO : 3
    1095 : 3
    As per BIS requirement, a nameplate shall be fixed on the body of the RO system at a prominent location. The nameplate shall be marked with these details:
    • Name of manufacturer
    • Brand name
    • Production serial number
    • Model name or code
    • Production rate in l/h
    • Percent recovery of product water
    • Maximum operating TDS level
    • Supply voltage, whether single- or three-phase, frequency, volts and wattage

    The product should include these details as well: namely address of manufacturer, manufacturing date, MRP, and warning/precaution note. An instruction manual containing proper method of operation and use of the purifier shall be supplied along with the purifier. The purifier may also be marked with the Standard mark.

    All the brands had provided the required information

    Aquaguard Enhance RO, UV : 2
    PRIDE : 2
    Minerala 90 Platinum : 2
    WAW35RW2RP : 2
    A. O. Smith Puritee Plus : 2
    Platina Silver RO : 2
    Wave : 2
    ROS 1375 : 2
    Pureit Marvella RO : 2
    1095 : 2
    As per the national standard, packing of RO purifier shall be sufficiently robust to give adequate protection from transportation damage. Being made from plastic material, the product has delicate assemblies and housing.
    • All the water purifiers were packed in thick, laminated paperboard carton supported by good-quality thermocol to give protection from damage.
    Aquaguard Enhance RO, UV : 1.5
    PRIDE : 2
    Minerala 90 Platinum : 2
    WAW35RW2RP : 2
    A. O. Smith Puritee Plus : 2
    Platina Silver RO : 2
    Wave : 2
    ROS 1375 : 2
    Pureit Marvella RO : 2
    1095 : 2
    A user’s manual for proper method of operation and use of the RO system shall be supplied along with the product. It shall also include details on the life and specification of all the filters/ consumables.
    • In the case of Aquaguard, no manual was provided with the unit.

    Pureit - All Pureit devices comply with the US EPA norm for 6, 4, 3 log reduction for bacteria, virus and cyst. We have supporting test reports from reputed internationally accredited labs to support this. We propose the following steps: Please repeat the test done on fresh devices. a) Please test in triplicates and not just a single device. b) The model you have tested was a recommendation of June 2014. We have discontinued that product. We suggest you test Pureit Marvella RO+UV SKU. c) To avoid any contamination during set-up and installation, please get the same done by an authorised Pureit technician only. d) Get the tests done again in some other authorised and approved lab.

    Aquaguard Enhance RO - Our major concern is the test result for microbial performance.Our RO system can remove bacteria and virus effectively because of the mechanical separation. Membrane porosity is less than 0.0001 micron, which is much less than the bacteria and virus cell size (bacteria 0.2 micron and virus 0.01 micron). Also, it can separate the ionic-level chemicals, which are much smaller than bacteria and virus. We suggest that you check the microbial study again by means of proper chlorine tablet disinfection of the storage tank of the new unit.

    Aquaguard - Our major concern is the test result for microbial performance. Our RO system can remove bacteria and virus effectively because of the mechanical separation. Membrane porosity is less than 0.0001 micron, which is much less than the bacteria and virus cell size (bacteria 0.2 micron and virus 0.01 micron). Also, it can separate the ionic-level chemicals, which are much smaller than bacteria and virus. We suggest that you check the microbial study again by means of proper chlorine tablet disinfection of the storage tank of the new unit.

    Tata Swach a) Arsenic: Reduction observed as per the Consumer Voice test is be in range of 56 per cent–59 per cent. However, in the tests as per NSF certification and in our own tests, the membrane/unit has demonstrated more that 90 per cent reduction consistently. b) Copper: Reduction in first week is surprisingly low and then there is drastic improvement. c) Mercury and cadmium: Reduction results show a trend opposite to that for copper.

    Zero B - a) Total dissolved salts: The unit was tested at an inlet TDS level of 1,976 ppm. However, the limit for inlet TDS level for Zero B Wave purifier is 1,500 ppm. The same should be taken for testing the TDS reduction of the product (with reference to IS 16240: 2015). b) Hardness: The inlet water hardness level is 500 ppm for Zero B Wave. The unit was challenged for a hardness level of 2,000 ppm, which exceeds the inlet water limits by a big margin. c) Chlorine: The level of chlorine spiked in test water was 8.7 ppm, whereas the inlet chlorine level for the product is nil. It does not claim to remove any chlorine from the treated water. d) Toxic chemicals: We are surprised that Zero B Wave has not performed well for arsenic and copper removal from the water, though our in-house test results are satisfactory. e) Microbial reduction: We are surprised that the results are contrary to our in-house test results.

    Aquaguard Enhance RO, UV : -
    PRIDE : -
    Minerala 90 Platinum : -
    WAW35RW2RP : -
    A. O. Smith Puritee Plus : -
    Platina Silver RO : -
    Wave : Total dissolved salts: Ground water was used as input water and your product recovery was 95.33 per cent (your claim is 95 per cent), which met the requirement. Chlorine: The test was carried out to check performance in the face of an abnormal condition that may occur in water supply from local corporations. Toxic matter: The test results as received from the laboratory have been reported to you and were reconfirmed by our designated lab.
    ROS 1375 : -
    Pureit Marvella RO : -
    1095 : -
    The designated NABL lab has been regularly doing tests of drinking water and water purifiers as per relevant Indian Standards. In fact, some of the manufacturers have been sending samples from their production line for testing to this lab. So, the test procedure itself is well-known to them and cannot be questioned. VOICE Society has been conducting comparative testing of consumer products since 1991. The technical advisors of VOICE Society closely monitor the activities of laboratories during testing of products. Regarding the suggestion for retesting for E. coli, MS2 virus and heavy metals, it must be noted that the comparative testing of RO systems has already taken approximately five months. Further, the laboratory has confirmed that they have retested, on a random basis, 30 per cent of the RO systems available with them and found that the retest results are very close to the earlier results. Further, it is a time-bound project and retesting of new models of all the 10 brands is not feasible. Since this is an ongoing activity by VOICE, we will give due consideration to manufacturers’ suggestions in the next round of testing of water purifiers. As of now, their comments have been noted in our records and are reproduced in the report along with our findings.