How to buy Water Purifier Guide

What is TDS in Water Purifier?

TDS stands for 'Total Dissolved Solids'. TDS in water means the amount of dissolved solids or chemicals in a unit weight of water. The definition for TDS is the weight of total dissolved solids in one million parts of the water containing the dissolved salts. TDS is usually expressed as 'ppm' which stands for 'parts per million' or as 'milligrams per liter' (mg/L).

How TDS of water is calculated?

We will demo how water TDS is calculated with an example: Assume there is 1 Kg of water containing dissolved salts, say 100 mg of Sodium Chloride and 100 mg of Calcium Chloride making a total weight of 200 grams of dissolved salts. The weight of water with dissolved solids is 1Kg = 1000x1000 mg or one million milligrams. So the 1 Kg of water containing 200mg of salts has a TDS of 200 ppm or 200 mg/L

What is safe TDS for drinking water?

The World Health Organization (WHO) and most Governments around the world has set an upper limit for TDS in water at 500 ppm (parts per million) or 500 milligrams per liter of water. So drinking water containing below 500 ppm TDS is safe for drinking. The ideal TDS for drinking water is between 200 and 300ppm. Most of our Public supplied tap water is safe with regards to TDS, but it is a good idea to check.

Is low TDS water harmful?

Low TDS water with no mineral content is not recommended for drinking. The World Health Organisation recommends that very low TDS water be remineralised before it is supplied to the general public from desalination plants to avoid corrosion in pipelines and as a precaution against any negative health effects of low water TDS. For more please visit our page WHO report regarding remineralization of desalinated low TDS water

Why TDS is important for water purifiers?

Water purifier companies needs to know the TDS of the raw water going into a water purifier because they have to be sure that the water purifier is able to purify the water to give drinking quality water. To meet local or international Drinking water standards, the purified water TDS should be below 500ppm. If the raw incoming water is above 500ppm TDS, then only an RO water purifier can be used. This is because only an RO water purifier can reduce the TDS of water by removing dissolved chemicals. The pressure required by an RO water purifier to push water through a RO membrane depends on the TDS of water. The higher the TDS of water, the more pressure is required for water to flow through the RO membrane. The pumps of home water purifiers cannot purify water with more than 2000ppm TDS. So the maximum TDS for home RO water purifier to work is 2000ppm.

What is Conductivity in water? What is the relation between Water TDS and Water Conductivity?

The TDS of water and the electrical conductivity (EC) of water has an almost linear relationship. The unit of Electrical Conductivity in water is expressed as Micro-Siemens per centimeter (at 25 °C). The electrical conductivity reading can be directly converted to the TDS of water using a conversion factor. The conversion factor is between 0.55 to 0.8 depending on the concentration of dissolved solids. Since handheld conductivity meters are small and cheap, electrical conductivity of water is now almost universally accepted as a measurement of the TDS in water. Pocket TDS meters working on EC values are widely used in the field to know water TDS.

What is ppm in water purifier?

PPM in water purifier stands for 'parts per million' and is a measure of how much of a substance there is in one million parts of water. It is used with TDS which is expressed in ppm. TDS ppm value of the raw water is an important criteria in the selection of water purifier.

Other common abbreviations used with water purifier

ANSI – American National Standards Institute
CBPs - Chlorination Disinfection by-products
CTO – Chlorine, Taste, Odor
DBPs - Disinfection by-products
EPA – Environmental Protection Agency
GAC – Granular Activated Carbon
GPD – Gallons per Day
HAA - Haloacetic Acids LPD - Liters per Day
MCL – Maximum Contaminant Level
NF - Nanofiltration
NTU - Nephelometric Turbidity Unit
NSF – National Sanitary Foundation of USA
PAC - Powdered Activated Carbon
ppb - Parts per billion
TFC – Thin Film Composite
THMs – Trihalomethanes
TSS - Total suspended solids VOC – Volatile Organic Compounds
WHO - World Health Organisation
WQA – Water Quality Association of USA

Best way to buy Water Purifiers in India

The best way to buy Water Purifiers in India is to first look at all models of Water Purifiers available online at the leading online Retailers in India. For example on the online webpage of All Water Purifiers available in India on, you will find the full range of Indian Water Purifiers complete with their best discounted price and full specifications. This is great information, and you can decide on which model of water purifier to buy. With the model of water purifier you want to buy finalised, you can go to local shops to try and find the model of water purifier you have chosen and see if you can get at similar price of that at In most cases the price from Amazon will be cheaper, because they buy in bulk from the manufacturers direct and they sell huge volumes because they are the world's largest and most trusted online retailer. If you buy from Amazon, they will arrange to have the water purifier installed in your house, usually free of charge.

Warranty and other facilities offered through Amazon are usually better than what you can get from local agents of water purifiers.

All pages in our website

Below are links to all the pages on this website and we hope you will make full use of all the great information about Indian Water Purifiers provided here.