Can RO Waste Water Be Used for Bathing?

Of all water purification technologies, reverse osmosis is the most efficient. In fact, if your home has high TDS levels, you’ve got no choice but to get a reverse osmosis system.

However, although highly reliable, RO systems often lead to water waste. An average water system wastes up to 80% of its input water.

Does this mean that you shouldn’t invest in an RO system? Not at all. Although the purifier wastes a lot of water, you can still put the reject water into use.

You can use RO wastewater to wash your car, water your garden, mop the floors, and bathe your pets, among other tasks.

Can RO waste water be used for bathing? Taking a bath in the waste water is a no-no. You should also never expose your hair to the water.

Why You Should Not Use RO Waste Water for Bathing

According to water experts, RO waste water contains high content of total dissolved solids, which make the water not only undrinkable but also unsafe to use on your skin and hair.

In some cases, the water becomes unsuitable for daily chores.

Water with a high TDS level contains a foul odor and taste hence unpleasant for you to drink. It can also cause certain skin problems like redness, itching, and irritation in the eyes.

Recent studies from Cambodia, Vietnam, India, and Ghana have actually associated skin diseases such as eczema to contact with untreated waste water.

Using the waste water to wash your hair will make it rough, dry, and brittle with time. Some minerals present in the water deposit on your scalp, making it dry and causing dandruff.

The presence of excess copper in the water leads to hair loss.

It’s also important to note that when using hard water, soap doesn’t lather. You’ll have a tough time taking a shower.

Using the water will also damage the showerhead and stain your bathroom tiles, something you’d rather not experience.

Water with high TDS has also been linked with severe medical conditions like infertility and stunted growth.

Do All RO Systems Produce Waste Water?

Although some RO systems claim to be zero waste, the truth is they still produce waste water. However, to satisfy their “zero waste” claim, they use an electric pump to circulate the waste water back into the system.

The pump can also push the concentrated water into the hot water line. This water ends up in the dishwasher.

How Often is RO Waste Water Produced?

An RO system produces waste water whenever it is producing pure water. This goes on until the storage tank is full and the faucet is turned off.

Note that while the RO faucet dispenses water into your glass relatively fast, the system produces water to refill the storage tank slowly.

How Can You Store RO Waste Water?

The easiest way to store the waste water would be by dropping the reject pipe in a bucket. However, if you spend too much water, the waste water will be a lot as well.

You don’t want to keep checking on the bucket so that it doesn’t overflow, right?

The best way to store the reject water is by dropping the RO waste pipe in a big tank (you can place the tank outside your kitchen).

You can then reuse the waste water to water your garden, wash the car, mop the floor, and wash utensils, among others.

How to Reduce Waste Water in RO Systems

Each drop of water counts, so there’s a need to ensure that a lot of water doesn’t go to waste. But as aforementioned, there’s no purified water from an RO system without waste water.

The good news is that you can reduce the amount of water that goes to waste. So, how do you go about it?

Listed below are a few ways of reducing waste water in RO systems.

  • Feed the reject water into a 2nd RO unit. This will help save up to 20% of the waste water, leaving you with remaining highly concentrated water.
  • Use electrodialysis. The method uses low energy and is thus a cost-effective way to purify the water.
  • Install a permeate pump. The pump increases the effectiveness of the RO system and reduces waste by 70%. For this method to work, ensure that you purchase a system that allows the attachment of an additional pump.


Although using RO waste water in the shower isn’t recommended by many, whether to bathe in it or not is a personal choice. In fact, some doctors encourage using TDS water for bathing, claiming that it’s beneficial.

However, we can all agree that even if you choose not to use the water for bathing, you can still recycle it for other purposes. Let not even a single drop go to waste when you can still use it for your daily chores.


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