For a long while I've wanted to be able to water our backyard ornamental garden with gray water. We already have a drip irrigation system and, while those are known for using water very efficiently, it still uses quite a lot of water. I researched gray water systems online and in books, but I didn't find any that would work similarly to a drip irrigation system by delivering the water to a large number of plants individually (actually, there are such systems, but they must be professionally installed and cost thousands of dollars).

Typical gray water garden systems deliver water to a few fruit trees or to large areas called "mulch basins" or they have water coming out of a hose that one can move around manually to different plants. What I wanted was a system that would take my gray water and distribute it to all of the places where the drip irrigation system goes. After almost six months of pondering this problem, last summer (2009), I hit upon a very simple solution that appears to work very well. I used it for a couple of months before our rainy season came, and then I switched the washing machine over to another water saving device, my laundry water recycler. Now the rainy season is coming to an end here in N. California, so I'll be reconnecting the irrigation system soon. Read on and you'll see how it works. I look forward to your comments and suggestions.

Step 1: Description of the Watering Technique

Although it took me six months to figure this out, the technique is extremely simple. First, I decided not to use any water from the kitchen for this gray water system, because of the difficulty of filtering out food particles. This system exclusively uses water from our clothes washing machine, which does contain a lot of lint, but that is easy to filter out. NOTE THAT, FOR HEALTH REASONS, IT IS NOT RECOMMENDED TO WATER VEGETABLES WITH GRAY WATER (fruit trees are OK though).

Drip irrigation systems water individual plants with little parts called "emitters" that allow the water to drip out. They are specially designed to not clog with roots or debris, but they require a fair amount of water pressure to operate and everything I have read about gray water systems warns that emitters will become clogged if you try and put gray water through them. However, there is another part, frequently used in drip irrigation systems that is the key to my system. It's called a 'barb x barb" connector and you can see a picture of one here (I'm not trying to endorse this vendor, it's just the first photo I found on the web). The barb x barb is made to connect a 1/4" diameter extension hose to a larger main line. In my system, I just put one of these barb x barbs next to each plant that will be watered. The first photo below shows one of  these "barb emitters" in action.

Each barb x barb has a hole that's maybe 1/16" in diameter, and this is large enough so that it won't clog (at least they haven't clogged after the first few months of use last summer and fall). In my first version of the system, I put the barb emitters at a slight upward angle, like in the photo. There were two problems with this: First, in some parts of the terrain, the pressure became low enough so that having the barbed emitter pointing up led to low or no water flow. Also, one of the nicest things about drip irrigation systems is that it delivers the water underground, so you get less evaporation. Putting the barb emitters straight down, sticking into the soil, would help the gravity/pressure problem and also the evaporation problem. However, just sticking the barb emitter into the soil could lead to clogging with particles or roots.

So, my second version goes as follows (see photos 2-5 below): I insert the barb x barb into the hose pointing straight down, then I wrap the middle section of the barb x barb with adhesive foam weather stripping. I then use a wooden dowel to poke a hole in the soil just under the barb emitter. I take a 3" length of irrigation tubing, fit it snugly over the weather stripping, and insert the tube into the hole in the ground. That way, the barb emitter has an empty space below it that is kept open by the tubing. I have had some of these in place since last fall and soon I'll check them to see if they are still working. Overall, I think the second version is a better idea, but there's something really gratifying about seeing the water squirting out of the above-ground barb emitters.

***UPDATE - the weatherstripping didn't hold up very well over the winter, so I'll need to find another way to plug up the hole. For now, I'm just leaving them - I have decided that pointing the x barb x straight down doesn't work in the long term, because the hole always fills up with soil, even when I put a piece of irrigation tubing inside the hole. Therefore, I recommend just having these "emitters" at an upward angle, as shown in the first photo.

Sometimes I don't have the main irrigation tube very near a plant. In those cases, I just insert a barb emitter nearby, and then insert a piece of 1/4' tubing to bring the water flow right to the plant (which is what barb x barbs are meant to do).

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<p>Hello, thanks for the post. Looks like a good system. As you've seen, one of the problems with using an open-flow type drip system like you have is that there are pressure differences due to length of pipe and elevation differences. Seems like maybe you've solved this problem, but another idea is to use 1/8&quot; poly tubing as your emitters. In the early days of drip irrigation, pressure would be regulated by using different lengths of small poly. Friction in the small poly would cause back pressure, and accordingly, you could regulate pressure by changing the length of the small tubing coming off of the 1/2&quot; poly. You would still have an open tube which would minimize clogging. The distribution tubing would have to be small diameter so that there would be frictional pressure loss. The down side of this, of course, is that you now have longer pieces of spaghetti tubing everywhere! Anyway, thanks again. I may look into doing something like this!</p>
Now that we are in the worst drought season , is so nice from people like you to share with us , how to use the gray water instead to let it go, beside saving water we are saving Money !!!
Wow that's really cool!&nbsp; I wish i could use this on my veggie garden, but like you mentioned - not a good idea!!&nbsp; thanks for sharing<br />
You can use it on your veggie gardens if you use environmental friendly soap ;-)
More recently, someone who knows a lot about gardening told me that she thinks it's OK to use gray water for a vegetable garden as long as you don't spray it on the leaves (i.e. as long as the water is delivered to the base of the plants. If that is true, then perhaps you could use this to grow vegetables. I think the jury is still out about what is actually safe or not safe to do with various types of gray water.
I have been using greywater in my ornamental AND edible garden for some time now, but I do it with soaker hoses and drip systems so it actually does not get on the plants. Plants do well and I do not really see a problem with health issues, considering what I know gets into my greywater which basically is detergent i.e. liquid soap for the dishes and a mild non bleach soap for clothes. <br> <br>I do not care that much about foodscraps in the grey water other than that it might block my hoses. Therefore most of my grey water from the kitchen goes to a basin in which food scraps sink and it is pumped into the garden through a filter. <br>My bathtub empties on the lawn and the trees whenever I pull the plug. <br> <br>I live in a fairly wet country though, but especially in the summer i would consider it a waste to just let it flow down the drain to the summer. <br> <br>Cost is part of the equation as water is cheap here. Most of my bill is because of taxes and levy's so I cannot make my solutions to be expensive. To give an example: By using my water wisely, I have been able to cut down from 60 m3/year to 30 m3/yr and now 15 m3/year. However, every m3 saved, saves me about 1 euro on my water bill. <br> <br>If I were to buy a rainwaterbarrell to collect rainwater, that would set me back about 200 euro's (yes, expensive) for say a 150 liter barrel. I would need to save 200 m3 water to even break even, which would be 1333 full barrels. That is just not worth it. <br> <br>Using graywater with relatively cheap hoses and a 15 euro pump is therefore more rewarding. For storage I use some 5 euro cement buckets that can contain I think 100 liters. I have seen some 1000 liter vessels that apparently are used to store foodstuffs and those come at 10 euro, at the local ebay but these just take up too much space. Yet, I think about buying one and just digging it in.
<p>FYI: The Laundry Drum has been superseded by the Laundry to <br>Landscape system. This system takes advantage of pressure from the washing <br>machine pump to send the water to several outlets up to 100ft away from the <br>machine. It can also serve outlets up to the height of the top of the machine. <br>There is an Instructable on this system at: <a href="http://www.instructables.com/id/Laundry-to-Landscape-Greywater-System/" rel="nofollow">http://www.instructables.com/id/Laundry-to-Landscape-Greywater-System/</a></p><p>The web information hub, and an instructional video for this <br>system are at <a href="http://oasisdesign.net/greywater/laundry/" rel="nofollow">http://oasisdesign.net/greywater/laundry/</a>. </p>
You are absolutely correct and I will change the instruct able accordingly.
You&rsquo;ve got a good little system working and it sounds like it costs practically nothing to put together. I would disagree that the gravel filter is an unnecessary component &ndash; it&rsquo;s surprising how grit and dirt can find their way into things and cause clogged-up pipes and blocked drains. Of course we can&rsquo;t avoid these issues no matter how well a filter system we put together, but every little bit helps reduce the amount of time we spend dealing with it.
Hi I am so glad to hear other people are doing this. My washer sits on a hill inside our house. The garden it waters is outside the wall and the garden is all ornamental and all runs downhill. We connected a short regular garden hose out the wall exit, then my husband added a soaker hose through the whole garden away from the house but weaving through all the bushes. We do laundry one day a week, usually one dark load, one white load. All the gray water is plenty to keep all the plants on the north side of the house perfectly watered. This is great in S. Ca. When it gets hotter out, we have a small pump we put in our bathtub, and pump all that gray water out to the front yard using a regular hose, and running it out to a sprinkler head on the lawn or in the flower beds. All our garden foods are watered w/reg. water. We have cut our water consumption by 30-40% by using gray water systems on both sides of the house. We also have exchanged out much of the original grass areas for indigenous plants that are drought tolerant! <br>Thanks for sharing how to do it if you are not as lucky as we are and need pumps to lift water up and out of the house! Ours was also just trial &amp; error, and seeing what worked and expanding it where we could! Hope you get others on board! <br>We heard of some of it through a book about using gray water called &quot;Damn Nation' also a good source for building gray water systems.
Here is my question................By using the washer used water......... I read through this and only see where it states using a certain washing compound so as to not harm the plants. Did you happen to come across any filtration system during your ventures of researching? The reason I ask is......if your spouse or a person uses bleach or some other agent in the machine then your plants may want to vine their way to you for payback. So........knowing that most chemicals will separate from the water over some time.......maybe helping this process along would develop a cleaner water supply. Not sure if a salt filter or charcoal type would work enough to clean the water. I do know the grass sure will grow and the weeds love it when the washer water is dumped onto the ground.
That's a very good question. First, we never use chlorine bleach in our household, because it is so toxic and bad for the environment. Instead, we use a non-chlorine bleach on our laundry and that doesn't seem to bother the plants. Now, sometimes we do need to use other detergents for &quot;special&quot; loads of clothing. In that case, the system has a pair of ball valves that divert the water down the regular sewer drain. I should add this information to the instructable. As far as having a chemical filter, I don't have enough knowledge of chemistry, but I think the easiest solution is to have a set of diverter valves and everyone in the household should know to send the water down the drain whenever they are not going to use a plant-compatible detergent.
I don't think chlorine bleach is necessarily bad for the environment or plants. <br><br>Here is an explanation on chlorine bleach: http://www.howstuffworks.com/question189.htm<br><br>And here is an explanation on the rinse cycle neutralization of chlorine bleach: http://www.clorox.com/blogs/dr-laundry/2011/10/17/neutralizing-rinse/<br><br>Chlorine is in our water. We drink it. And water plants with it. A chlorine bleach cycle will probably be safer than detergents, which can be more harmful due to its chemistry of bonding to dirt/grease. I would drink a chlorine cycle glass of laundry water than a detergent cycle. Living things can tolerate everything in moderation - arsenic for instance. <br><br>
What I have read about graywater is different. They say if you use it, make sure it stays off the plant and is aimed at the ground. It is only when the water gets on the plants that it might be hazardous to people and especially if you do not properly wash the food before eating. Think about it...compost has bacteria. It is constantly used to feed the plants. Also when you look up what to use and not to use in composters, they warn many things will make a strong odor and attract predators and insect pests. <br> <br>Any clean watering system can even be a problem is you have it hooked into the house watering system without a backflow valve. With appropriate measures it is safe to use bath and shower water for watering if you do not use chemicalized hair and body care products and aim the water to emit gently (so it doesn't splash) and apply to the earth and not the plant itself..
no need for the barb, just drill through the black poly with a 2 - 3 mm drill bit. At the end of the run of poly put an elbow &amp; a short length (20 - 40 cm) of poly pointing straight up. This will provide a bit of back pressure so all holes will emit water. The run of the poly needs to be flat to slightly down hill. Easiest filter I've found for the amazing amount of fluff coming out of the washing machine is a length of pantihose leg tied over the outlet hose. It needs to be changed every three or four washes.<br>Don
Reading various systems. Your tank looks nicely set up. I want to know what is that beautiful plant that is growing under your storage tank in step 3? I would love to get one of those growing in my garden.
Unfortunately, I don't know what the plant is called. The flowers are a BRILLIANT orange and they last for only a week or two in the spring. I've seen it in our local nursery, so I'll post the name if I find out.
Clivia. We have some ourselves here in Waitakere City (two more weeks 'til we're part of the Auckland &quot;supercity&quot; :[ ).
Thanks for the response, if your plant blooms again could you get a close up pick and post it. I might know what it is but need a closer picture of the blossom. Would greatly appreciate it. Again, nice job on the tank and all.

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Bio: By day I'm a mechanical engineer at a university laboratory. In my free time, I do my own projects.
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