Can I Use Reverse Osmosis Waste Water for Washing Clothes?

Can I Use Reverse Osmosis Waste Water for Washing Clothes?

Reverse Osmosis (RO) filtration systems purify water through a rigorous process to give you safe drinking water. However, there is a lot of water wasted in the process. If you are wondering whether you can use this waste water for household chores such as washing your clothes, you’re at the right place.

You can use reverse osmosis waste water for washing clothes. The salts present in the waste water aid in the removal of dirt and stains. However, the high amounts of Total Dissolved Solids (TDS) in the waste water can affect the quality of delicate fabric and make your clothes feel stiff.

RO filtration systems give us pure drinking water, but in doing so they waste up to 20 gallons of water for purifying every 3-4 gallons of purified water. This is quite a lot of water to waste when facing a clean water shortage crisis. This reject, or waste water, can be used for chores such as washing clothes. Let’s look at how this can be done.

Read my comprehensive article about reverse osmosis.

Why Should You Use RO Waste Water for Washing Clothes?

Reverse osmosis systems push water through a semipermeable membrane with tiny pores that only allow water and molecules smaller than that of water to pass through. This process wastes a lot of water that can be rerouted and used for your laundry.

Here is why using your RO waste water for washing clothes is a good idea:

1. It removes dirt properly

Reject water from a Reverse Osmosis system contains very high amounts of TDS and salts such as calcium, magnesium, sodium, lead, and other metals. These are the same particles that are part of many detergent formulas and make the removal of dirt and stains easier.

2. It is eco-friendly

Water is a scarce resource. Many populations across the globe lack access to clean water for usage in their homes and for drinking purposes. In this case, it just doesn’t make sense to waste gallons upon gallons of water. Using RO waste water is an environmentally-friendly choice that you can be a part of, making sure you do not contribute towards water wastage.

3. It saves you money

When an RO system rejects about 20 gallons to give you 4 gallons of pure water, it is natural that your water usage and the bill will be high. However, you can use the reject water to wash your clothes, saving you water and money.

How to Save RO Waste Water for Washing Clothes?

If you’ve decided to recycle the waste water from your Reverse Osmosis system for doing laundry, you can do this in the following three ways:

1. Collect RO waste water in a vessel or bucket

The first method is pretty straightforward, but it requires space where your reverse osmosis unit is installed. You will simply need to place the RO waste water line in a clean bucket or dustbin. This solution works well where there isn’t a lot of RO water usage.

If you are utilizing a good amount of drinking water, like 20 liters, then your reverse osmosis system will waste about 50-60 liters of water, and collecting all this water in a small vessel or a dustbin will be quite a hassle.

Not only would you have to make sure you empty the vessel in a timely manner, but you will also have to keep an eye on it, so it doesn’t end up overflowing.

2. Collect water in a large holding tank

If you have a high level of reverse osmosis water usage, then you could choose this option. Place a large holding tank right outside your kitchen and then extend your RO waste water pipe to the holding tank. This way, you can use the water to wash clothes later or for other purposes.

3. Collect water in a tank right above your machine

If you want to make your life even easier, install a holding tank with a fixture above the washing machine. The waste water pipe will be extended to collect water here, or you can install a pump in the larger tank and connect it to your automatic machine’s water inlet.

This way, you won’t have to carry bucket loads of water to your machine every time you do laundry.

Tips for Washing Clothes with RO Waste Water

Using reverse osmosis waste water is a great choice if you want to save water. However, if your water source has a high level of TDS and hardness, it can impact the quality of your clothing. There are some guidelines you can follow to ensure your clothes turn out well-washed:

1.   Use a high-quality detergent

The number one tip for washing clothes with RO waste water is to use low-pH detergents and ingredients that are very good at trapping the extra minerals in the RO waste water before they can attach to your clothes.

2. Use a fabric softener

Fabric softeners are found right next to detergents in grocery stores. Their main job is to coat the surface of clothes with a specialty chemical that stops the minerals from attaching to your clothes.

3. Use warmer water

Using warm waste water can increase the intensity of the chemical reactions during the washing process. This will ensure that more dirt, stains and TDS are washed away from your clothes.

Frequently Asked Questions

1. Can you use RO reject water for bathing?

RO reject water has high amounts of minerals and salts that can dry out your hair and skin, so it is not a good idea to use it for bathing.

2. Can RO waste water damage a washing machine?

Reverse osmosis waste water is suitable for washing clothes with a washing machine. However, if the waste water has very high levels of TDS, i.e., above 1200 ppm, it does have the potential to cause mineral buildup in the machinery and damage it.

3. Does more water mean cleaner clothes?

Adding more water than necessary to your washing machine can result in dirtier clothes because it hinders clothes from rubbing against each other. Friction from clothes rubbing each other in a washing machine is essential for removing dirt and stains.

4. Can I wash my dishes with reverse osmosis reject water?

You can safely wash your dishes with reverse osmosis waste water. You will need to collect the waste water in a holding tank and connect it to your dishwasher or provide a faucet at your sink for washing and pre-rinsing kitchen utensils.

Final Thoughts

We hope you find this article helpful in using RO waste water for washing clothes. You can use RO waste water to do your regular laundry if you collect it properly and use it with a suitable detergent. Utilizing the reverse osmosis reject or waste water is an excellent way to save money and water.

Boch Richard

Richard Boch is a chemical engineer responsible for designing water filtration systems for industrial and residential customers. He has more than 20 years of experience with ion exchange, activated carbon, and reverse osmosis. Richard's expertise has made him a go-to source for municipalities and businesses looking to improve their water quality. When he's not working, Richard enjoys spending time with his wife and two young children. You can also follow him on LinkedIn, Twitter and Facebook.

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