Is RO Water Good or Bad for Health? What You Should Know

By Sanchit Jain, RO technician and owner of Sanchit Enterprises, Roorkee (since 2014). Updated October 2026.

Is RO water good for health? For most homes with hard or contaminated water, yes: RO removes dissolved salts and many harmful substances that ordinary filters cannot. The concern people raise is that RO also removes useful minerals. Modern purifiers deal with this through a TDS controller or a mineral cartridge, and most of our minerals come from food rather than water anyway.

The honest answer is that RO is right when your input water needs it, and unnecessary when it does not. Here is how to tell the difference.

This guide explains water quality, not medical advice. If you have a health condition, ask your doctor about your drinking water.

What RO actually removes

A reverse osmosis membrane has extremely fine pores. Water is pushed through it, and most dissolved substances are left behind and flushed away. That includes:

• Excess dissolved salts that make water taste salty or bitter
• Hardness that leaves white scale on kettles and taps
• Many heavy metals such as lead and arsenic
• Excess fluoride and nitrates

Most home purifiers add a UV or UF stage after RO to deal with bacteria and viruses, which is why you will often see RO+UV or RO+UV+UF on the label.

The mineral question: is RO water bad for health?

RO also removes calcium and magnesium, and water with almost no minerals tastes flat. The World Health Organization has discussed the long-term drinking of very low-mineral water, and its Guidelines for drinking-water quality are the main global reference on safe water.

In practice this is why good purifiers have a TDS controller or a mineral stage. They blend in a little filtered water or add minerals back, so the water is purified but not stripped bare. A technician should set this for your water rather than leaving it at the factory setting.

What the standards say about TDS

TDS, or total dissolved solids, is the simplest measure of how much is dissolved in your water. India’s drinking water standard, BIS IS 10500, sets 500 mg/L as the acceptable limit and allows up to 2000 mg/L only where no other source is available.

If your tap or borewell water is well above 500 mg/L, an RO purifier makes sense. If it is low to begin with, an RO may remove more than it needs to.

When you do not need an RO

Some municipal supplies are already low in dissolved solids. For water like that, a UV or UV+UF purifier kills germs without removing minerals, and wastes no water. Many old homes in Roorkee and Haridwar use both supply water and a borewell, which is why we always test before recommending anything.

We test your water for free before suggesting a purifier. See buying a water purifier in Roorkee.

Is RO water safe for kidneys?

For healthy people, there is no good evidence that properly purified RO water harms the kidneys. What matters most for kidney health is drinking enough clean water. RO water that is within the BIS limits, with the TDS set correctly, is suitable for daily drinking.

If you have kidney disease or a kidney stone history, follow your doctor’s advice on what to drink. Some patients are told to watch minerals such as potassium or calcium, which can matter more with mineral-added or alkaline water. See also RO vs alkaline water.

How to keep RO water healthy

• Get the TDS set for your water after installation and after every service.
• Change filters on time. An exhausted carbon filter lets taste and smell back in.
• Clean the storage tank at every service. Even purified water can pick up germs from a dirty tank.
• Check that the UV lamp still works. It can fail while the purifier keeps running.

Regular RO service takes care of all four.

So, is RO water good for health in your home?

Is RO water good for health in your particular home? It depends on three things: what your input water contains, whether the TDS is set correctly, and whether the purifier is maintained. Get those right and the answer is yes.

People often ask us is RO water good for health in the long run. With a correct TDS setting and regular service, it gives clean, safe water every day. Is RO water good for health if the tank is never cleaned? No, and that is the part most homes forget.

Is RO water good for health: frequently asked questions

Is RO water safe for children?

Properly maintained RO water with the TDS set correctly is safe for the whole family. A dirty tank or exhausted filters are bigger risks than the RO itself.

Does RO water cause mineral deficiency?

Most minerals come from food. Purifiers with a TDS controller or mineral stage also keep some minerals in the water.

What TDS is good for drinking water?

BIS IS 10500 sets 500 mg/L as the acceptable limit. A technician can set your purifier so the output is purified but not stripped of all minerals.

Do I need RO if my water TDS is low?

Often not. A UV or UV+UF purifier may be enough. Get your water tested first.

Is RO water hard on the kidneys?

For healthy people, no. Properly purified RO water within BIS limits is suitable for daily drinking. People with kidney disease should follow their doctor.

Can I drink RO water every day?

Yes, as long as the purifier is serviced on time and the TDS is set correctly.

Related: water purifier dealer in Roorkee · RO service in Roorkee · RO filter change

More RO guides: RO or Aquaguard: which is better? · What decides RO service cost · Disadvantages of RO water · RO water tastes salty?