Simple Laundry Greywater System




In Southern California, we are dealing with water restrictions due to years of continuous drought and water shortages. Here is one way to start saving on irrigation water. Our washer is in the garage, so it is easy to run this set up out to the yard. It is working great for me and I am saving a ton of water on irrigating my ornamental plants and trees. I already had the trash can and a 3/4 inch garden hose, so this set up only cost me about $10 plus the cost of another 3/4 inch hose (about $30).

Make sure you only use biodegradable laundry detergent labeled for greywater use. Also, there are a few more rules for using greywater so be sure to read those at the end of this instructable.

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Step 1: Laundry Greywater Parts


5/8 inch spade drill bit

Garden Hose Adapter 3/4 " MH X 1/2" MIP- part is in the faucet section of Home Depot, not in the garden hose or irrigation area. (Watts brand A-663 GH3)

'Faucet Rosette Washer and Nut (1/2" IPS) - Danco brand

3/4" diameter garden hose

Trash can (I think mine is 20 gall, but use a larger one)

Step 2: Cut Hole, Insert Garden Hose Adapter

Cut a hole in the bottom of the trash can using a 5/8 inch spade drill bit (I had to shave off extra to make the adapter fit)

Screw in the garden hose adapter (make sure the hose fitting side is on the outside of the trash can).

Step 3: Attach Washer/Nut

Secure adapter into hole with a Danco brand Faucet Rosette Washer and Nut (1/2" IPS) on the inside of the trash can. (I have not sealed it with any silicone, but I have no leaks).

Step 4: Attach 3/4 Inch Garden Hose

Step #4
Attach a 3/4" diameter garden hose (this is the largest size diameter hose sold at Home Depot- most hoses are 5/8") to the end coming out of the trash can. I actually have 2 x 50 feet garden hoses (100 ft long total) connected end to end so that I can water at the far end of my backyard. Just place the end of the garden hose wherever you want to water. I move mine around as needed, but be sure you have no kinks or obstructions.

Step 5: Catch It!

When I start laundry, I bring my greywater trash can inside the garage and place it on top of a cooler (or cinder blocks). You want it high enough to drain well. I make sure the garden hose is on tight and then place the laundry drain pipe into the trash can. As it fills, it automatically drains to wherever I have placed the garden hose. Our back yard has only slight elevation and the trash can is above the hose line. We save over 40 gallons of water on a large load. Once made, this is a super-easy system.

Step 6: Let It Flow!


1. Use only detergent labeled for greywater use (most grocery/market stores sell it now).
2. Never spray greywater, it has to be applied directly to the soil. Do not use it to water vegetables. It is ok to water fruit trees, ornamental plants, trees shrubs if applied to the soil (best if applied under a layer of mulch).
3. Never let greywater go down the storm drain. Make sure you water away from where it could ever overflow out of your yard in to the storm drain.
4. Do not water lawns with greywater. Do not use greywater where people will come in contact with it.
5. Make sure trash can is elevated on a cooler or cinder blocks to allow for good flow.
6.Check for kinks/obstructions in the hose line (could cause backup).
7. If you need to use bleach or non-greywater detergents, be sure you move the line to go back down the sewer drain.

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15 Discussions


FYI: The Laundry Drum has been superseded by the Laundry to
Landscape system. This system takes advantage of pressure from the washing
machine pump to send the water to several outlets up to 100ft away from the
machine. It can also serve outlets up to the height of the top of the machine.
There is an Instructable on this system at:

The web information hub, and an instructional video for this
system are at


6 years ago on Introduction

Where I come from most years conserving water is like people in the desert conserving sand. I would have no problem putting my laundry water on my garden unless you work in a barn and your clothes are covered with raw manure I can't imagine what would be in it that is not already in the dirt.
Shaklee laundry soap and Basic H are non toxic as well as biodegradable. They have been used all over the world in this way. Farmers use Basic H on their fields. I use it as plant invigorator.


7 years ago on Introduction

There are a couple of things you can do to make the water safer.
1) How to Make Water Filter for Removing Chloramine and other impurities
By: Joe Hing Kwok Chu
Material needed:
1. Water tank with outlet
2. Clean sand
3. Activated catalytic carbon
4. Coconut fiber (from coconut husk)
Place fiber on the bottom of tank.
Place carbon on top of fiber.
Add another layer of fiber on top of carbon
Place sand on top.
These layers can be repeated 2 or 3 times.
The material can be replaced after the filter has become dirty.
How This Water Filter Works
The coconut fiber possesses the best fungus inhibiting effect of natural fiber known. The fiber laid at the bottom of the water tank helps holding the activated carbon to stay in the tank and also help filter out some larger solid pieces of impurities in the water.
The better activated carbon is made from coconut shells and are not chemical activated like wood charcoal or coal; therefore it is suitable for filtering drinking water. Activated carbon is full of pores. This network of connected pores inside the carbon creates a large surface area, about 1000 square meter per gram of carbon. Activated carbon filters out impurities from the water by transferring the impurities from the water to the surface of the carbon. Activated carbon acts as a catalyst in chemical reaction in removing chloramine. The transferring impurities involves 2 methods:
1. Physical absorption, and
2. Chemical absorption (chemi-sorption)
The physical absorption is the gravitational force and magnetic force that pull the impurities to the pores of the activated carbon granules.
The oxidation-reduction (redox) and chemical absorption occur on the surface of the activation carbon while the physical absorption occurs in the pores of the activated carbon. The redox and chemical absorption actually change the chemicals into new chemicals. For example, the chlorine is change into chloride and the chloramine is degraded by the reaction of oxidation chemistries on the surface activated carbon.
the next one may be a little more expensive, but if you live in an area consistently plagued by drought, it would be worth it. I'm putting the link to the information on here since it won't let me paste it.

I would still use a biodegradable/phosphate free detergent. The great thing about this is that the water can safely be stored in a pond that has aeration and slowly released through a drip system to your garden or trees.


7 years ago on Introduction

If you use this system over a long period, you may have to add water to the sewer line to keep your trap from drying out and venting sewer gas back into your laundry room. Great idea, though.


8 years ago on Step 6

Years ago, my friend made a system for watering his lawn and Italian cypress trees. They only used the rinse water and put the soapy wash water down the drain. After 2 or 3 years, the lawn was nice, no residue could be seen. They used city water to water the garden.

As for not letting it go where people can come in contact with any soap or sweat from your clothes, heck, they say your detergents are still there after washing and you sleep on your sheets and it gets absorbed into your skin. But that's why he did not put the wash water on the lawn, he didn't want bacteria from the wash on his lawn.

His washer was in the end of the kitchen. He could hear when the machine stopped its first spin and changed the hose over to his recycle tank which was an old galvanized wash pan with a garden hose going out the back door.

I have thought of this the last year, living in Los Angeles also. I like your idea about biogradable detergent and will try it. If it doesn't get my chothes clean as Tide, I'm going to the rince water only method. I'm not wearing grey clothes lol.

Great Instructable :)


8 years ago on Introduction

Nice job. I know that some septic systems use a sprinkler of sorts to increase aeration of a septic intake tank (if that makes sense.) I imagine it could be a problem with a barrel full of soap but a day's worth of aeration could help degrade and bind any chemicals that would otherwise give your lawn a headache (phosphates, nitrates, etc.) For the fun of it, you could also make a small scale marsh to discharge the water through.

But all of that is just icing. You've done a great job with a basic cake recipe. Reproducible, cheap and cheerful. Well done.

peds OT

9 years ago on Introduction

Grey water is not ideal for plants that prefer acid soil, rhodies, blueberries, etc because the soap will change the pH.  So use with moderation.  Also see greywater guerillas website for more info


9 years ago on Introduction

I live on a mountain, and I use rain water caught in barrels for washing. I have an old wringer washer that just dumps out after I wash clothes. To save water, I wash loads according to degree of dirtiness, ending with jeans and other workclothes. After I am done, I save the grey water in a bucket and use it to flush my toilet. If you use homemade soap like me, or enviro-friendly store bought soap, It should be safe for city sewer systems.  I like the idea that you can use it on fruit trees--I have a huge blackberry patch on my property. Anyone know if it would be safe to use on the wild fruit?


9 years ago on Introduction

Why not save the grey water as wash-water for a 2nd load. It washes the duds and gets pumped into the sewage. Then you save the rinse/grey water
as wash water for each load.


10 years ago on Introduction

 I've also been interested in using grey water and found this Instructable to be a simple start. I do have some questions on the 'rules' for using greywater.
  • Why must grey water NOT be used on grass?
  • Why must grey water NOT be allowed to go into storm drains?
  • We have a large retention pond (several houses long). If grey water got in there, could it do damage? There are currently several varieties of fish and turtles that live in the pond.

Thanks for the information,

2 replies

Reply 9 years ago on Introduction

I think the reason for not putting it on your grass is it will be hard to water the grass without a sprinkler. For health reasons you shouldn't use a sprinkler device distribute greywater as it may be inhaled by a human.


Reply 10 years ago on Introduction

There is no reason why your grey water cannot be used on your grass if it is used immediatly and not stored for any length of time. If grey water is stored, it becomes a breeding ground for bacteria and could be a health risk. However if used immediatly it exits the home - its safe as long as there are no members of the family that are ill (upset gut etc) I like to use the example of a child playing in the bath. If you are happy with a toddler playing in his bath water and putting facecloths in his/her mouth - then its safe to irrigate with some 30 seconds later.

One of the reasons grey water should not be discharged into storm water drains is because it  contains phosphates ( which is found in common fertilisers). However phosphates cause algae blooms if grey water enters rivers and/or lakes. 

Grey water must be kept out of the retention pond. Phosphates and nitrates will be be harmfull to any life in the pond. We also use chemicals to clean our tubs and showers and these will also end up in the pond. Used in moderation in the home, this grey water will not effect your garden

Hope this helps 


9 years ago on Introduction

You should have too some organic detergent I don't think plants will love that dirty water. Why don't you collect rain water it's cleaner? I think it's ok if you have checked all laws. :)


10 years ago on Step 6

always check your local laws on grey water - a friend of mine always uses one of the little round "sprinklers for distribution of her grey water


10 years ago on Introduction

I so want to do this, you've come up with the super simple version. I put a bucket under the outlet hose in the sink that our washer drains to and fill up on rare occasion. The big thing is converting enough of your household needs to use greywater to get a good return on investment. I suppose water restictions would make this very worthwhile. Simple is better. Nice...