Introduction: Water Recycler (Grey Water)

Picture of Water Recycler (Grey Water)

The area that I live in has been in a drought for a year or more. As such we now have water restrictions on washing the car, watering the garden etc. Initially I set up a drainage hose from the washing machine outlet to containers outside to enable me to collect the waste water so I could water the garden. This process worked fine except for the back breaking work of emptying the waste water (grey water) onto various places in the garden.

The next stage was to develop an automatic system that would distribute the grey water into the garden and have the following features.
1) Filter the water before sending it to the garden.
2) Automatic pump to allow water to be delivered to the high end of the garden.
3) Timer to prevent water stagnating in the tank.

The system uses a wheeled trash bin which is made out of 5mm thick plastic (nice and sturdy). Grey water comes into the top of the bin into a filter. When the bin fills to around 3/4 full, a water level switch triggers the pump controller to turn on the pump sitting at the bottom of the bin. The pump continues to operate until the lower water level switch is triggered.

The pump controller also has some logic built into the program to detect if water is in the bin but not high enough to operate the high water level switch. If this situation occurs, at 10 hour timer is started. If the water stays in the bin for 10 hours the pump will start and empty the bin. This stops the water from stagnating. I also have another timer that detects the run time of the pump. If the pump runs for longer than an hour (without any of the level switches being triggered) then the fault LED will be lit and all pumping will stop. This would indicate that the output pipe is blocked.

Step 1: The Schematic of the Pump Controller.

Picture of The Schematic of the Pump Controller.

The pump controller is built around a PICAXE 8m PIC. The reason I chose this particular PIC is that it is programmed in BASIC and is cheap ($4 AUD) and I can't program in C to save myself.

There are 3 float sensor switches used in the project. Two of these float sensor switches detect high and low water levels of the tank. The third sensor detects when the water filter needs a clean.

The controller also drives 3 LED's that are mounted on a remote indicator panel in the laundry that indicates pump running, filter clean required & fault condition.

The transformer I used in the project has a 24VAC tap that I was going to use to power some water solenoids. Any voltage from 12VAC to 18VAC can power the circuit. The voltage regulator doesn't get hot as the PIC only draws a few milliamps. I also use a resistor to reduce the unregulated voltage to the pump relay which may need to be altered depending on the relay voltage.

Step 2: Make the PCB.

Picture of Make the PCB.

Make your PCB. I used the tried and tested toner transfer method. The attached schematic & PCB were done in Eagle. I'm just learning Eagle so please excuse my mistakes. I placed vias on most of the pads to increase there size. I found I just couldn't get the DRC rules right so I found this method easier.

Parts List
1x 8 pin IC socket.
1x 7805 5v regulator.
1x 1amp bridge rectifier.
2x PCB mount fuse holders for M205 fuse.
1x 500mA M205 fuse.
3x BC639 transistors.
12V relay with switch contacts rated at 240VAC 10 Amps.
3x 3way PCB screw terminal blocks 5mm spacing.
2x 2way PCB screw terminal blocks 5mm spacing.
1x 1N4004 diode.
1x 1000uf 35v (or higher) electrolytic capacitor.
6x 2.7K resistors 1/4 watt.
3x 10K resistors 1/4 watt.
1x 100nf ceramic or mylar capacitor.
1x 180ohm 1 watt resistor - note resistance and wattage may need to be varied due to supply voltage.
2x 5mm green LEDs.
1x 5mm red LED.
1x 5mm amber LED.
1x weatherproof box to house the controller.
1x small box to house the 3 status LEDs.
4x waterproof cable grommets with internal rubber glands.
Various size cable ties, heat shrink.

Parts list for the PIC programmer circuit
1x 10K resistor.
1x 22K resistor.
1x 9 PIN female DB connector (this connects to your PC / MAC).

Step 3: Programming the PIC

Picture of Programming the PIC

The PICAXE-8M is programmed via the serial port of your PC. The PICAXE editor and data sheets can be obtained from the following URL:-

The code is easily modified however I didn't put any "in circuit" program headers on the PCB so you'll have to take the PIC out to re-program.

The schematic & PCB could be used for other switching / sensor purposes with the required code changes made.

Here's the BASIC code:-

;Grey water controller MK2

symbol PUMP=0 ; name output 0 as the PUMP
symbol ERROR_LED=1 ; name the output 1 as the error (fault) LED

;high waterfloat switch = input 3, low water float switch = input 4

let dirs=%0000111
let pins=%0000000 ;ensure all outputs low

;float switches are inverse logic, a 0 means it is turned on
if input3=0 and input4=0 then debounce ;high water float mark
if input4=0 then inc_timer ;low water float mark
goto main_loop

let w0=w0+1
if w0=36000 then start_pump ;if water is in the tank for 10 hours, start pump
pause 1000 ;pause 1 second
goto main_loop

pause 500
if input3=1 then main_loop ;check if the float is still high

high PUMP ;turn on pump relay

if input4=1 then stop_pump ;check to see if low water
if w1=3600 then pump_error ;error if pumps operates continuously for more than 60 minutes
let w1=w1+1
pause 1000
goto pump_loop

low PUMP ;stop pump
let w0=0 ;reset stale water counter
let w1=0 ;reset error counter
goto main_loop

low PUMP ;stop the pump

if input4=1 then exit_loop ;stay errored until tank empty
pause 500
pause 500
goto error_loop

let w0=0 ;reset counters
let w1=0
low ERROR_LED ;reset error LED
goto main_loop

I set up the following circuit up on a prototyping board to program the PIC.

Step 4: The Mechanicals of the Project.

Picture of The Mechanicals of the Project.

The pump I chose was a submersible type designed for dirty water. It was suppose to operate in the vertical position but it would not reliably deliver water after a few months of operation. I tracked the issue down to air in the impeller chamber. There was a small ball bearing that was suppose to let air escape and close the bleed hole when the pump was running. However grey water has soap in it. After some months this ball bearing was stuck in its hole preventing air escaping from the chamber.

The solution was to put the pump on its side to prevent air pockets from being created. A year later I think this mounting method was not in the best interest of the pump. The pump seems to have lost its punch, it still delivers water but not like it use to. I suspect the pump being on it side has let water seep into the motor bearings (only a theory).

The pump is mounted on a aluminum frame. The frame is secured to the bin at the top of the frame. This was done so that the bin is watertight. Any mounting holes in the bin are above the high water line. Also mounted on the aluminum frame is the 2 water level switches. These are sealed magnet & reed switch units and can be purchased at spa shops or here in Australia at Jaycar or Altronics

To stop the pump from sliding around at the bottom of the bin it is cable tied to the aluminum frame.

Step 5: Wiring It All Up.

Picture of Wiring It All Up.

The following instructions show how to wire up the controller to the pump and remote indicator panel.

For the power cord I used a power extension lead and chopped it in half. This method left me with a molded power socket for the lead that goes to the pump. That way I didn't need to butcher the existing power cord on the pump. Alternatively you could mount a power socket on the case of the controller.

Please ensure that the earth wire (green/yellow stripe) is connected from the power cord through to the lead going to the pump. To join the earth wires together I used a crimp lug that was then bolted to the transformer chassis (using star washer to ensure a good connection to the metal).

The transformer I used had flexible leads so I crimped the 3 neutral wires (blue) together using an insulated joiner (then heatshrink was placed over it).

To connect the 3 LED's on the remote indicator panel you need 4 wires. You can use Cat5 or phone cable. I also had a power LED that is mounted in the controller box itself (not remotely).

The remote indicator panel is made from a hobby box that you can purchase from electronic stores like Jaycar, Altronics, Dick Smith, Radio Shack etc. The lettering I used was Letraset rub on lettering. The weatherproof polycarbonate box was purchased from an electronic supply store. Ensure that it can be sealed to prevent rain from getting in.

Since you will be having a pump that is submerged in water you must power the controller / pump from a safety switch protected power outlet. You can find cheap extension cords that have a safety switch built into the plug.

Step 6: Setting It Up Outside

Picture of Setting It Up Outside

I installed the Grey Water recycling bin up the side of the house that has all the plumbing. The recycler needs a sewage inlet that the overflow pipe can connect to. It also needs a hose run from the outlet of the washing machine to the inlet (top) of the bin. You can connect your shower or bath to the bin but this would require major plumbing alterations. Also hear in Australia any permanent plumbing needs to be carried out by a licensed plumber. You also must not use the recycler for Black Water e.g. water from sinks & toilets for obvious smelly reasons.

The outlet of the recycler is feed into the garden via 19mm (3/4" I think) garden poly tubing. This is nice and cheap. In the garden I have buried slotted poly drainage pipe which the Grey Water empties into. You can't use sprinklers as the soap in the water will clog any small nozzles and also spraying the water could be a health hazard as any water left in the tubing will become stagnant. There is also the risk of inhaling waterborne bacteria so don't use sprinklers.

I have also noticed a range of low pressure drip hoses designed for tank water / gravity feed irrigation systems. I'm not too sure how long these hoses would last with the soap content in the water. They also could be used to deliver the water to the required locations in the garden.


aldwindarwin (author)2017-09-01

Hi sir what would be the possible recommendation for this device to make a new improvement and make it more useful?

beetpickles (author)2014-04-23

My plants love greywater! It's not recommended to use greywater on food crops that grow underground (carrots, potatoes, etc), but in general it is fine to use on the garden. The plants like the nutrients. I have a low tech system that delivers my laundry water to berry bushes and cherry trees: I am careful to use only Eco soap with no salts or phosphates and have a three way valve to send the water to the sewer if I need to use bleach or am washing something that's not good for them. My plants are very happy and growing like crazy!

lionelb (author)2013-11-01

What about using the dish-washer and clothes washing machines' waste water to flush your toilets .... hygienic too !

4 Pumps (author)2013-08-19


Good to see someone thinking ahead. You could use a similar system to pump grey water with a submersible pump. You could use a pump with a rigid float and a timer on the power source. This way you could set the system up with a much lower volume of water to get it started. It would also save you having to design a controller but it looks like you are pretty good with that anyway :)

hhamilton2 (author)2011-10-13

Since you have an interest in sustainability, you might like this as well.

G Gurunadha Reddy (author)2010-11-25

How does this stuff work.

G Gurunadha Reddy (author)2010-11-23

Does this project have a purification or afitration device.

harry88 (author)2010-07-04


harry88 (author)2010-07-03

does it have to run on ac i was thinking running it on solar pannels

slemke (author)harry882010-07-04

Just connect the 12VDC (I'm assuming the output is 12V) from the solar panel up to the AC terminals on the PCB. Don't use the AC transformer. This will then feed 12VDC strait into the voltage regulator. Don't worry about the polarity of the 12V from the solar panel as the bridge rectifier in the circuit will sort it out. Note that you may need to replace the resistor just above the relay with a wire link as I originally used a 12V relay which was running off 20V. Use a 12VDC pump.

notsogoldenoldie (author)2010-04-13


for those interested in grey-water systems, check out Art Ludwig's 'laundry to landscape' system. It's similar to slemke's but uses the washing machine pump to directly deliver the water to the mulch-beds, bypassing the need for a sump/bilge pump. I believe Art also uses a fairly large bore pipe to avoid lint blockages.

Here's the link...

gardenResQ (author)2009-10-16

Grey is now the new green. Grey water, if utilised immediately in exits your bathroom, is considered safe. However we need to be responsible with our grey water and how we use it. Go easy on chemicals in the bathroom when cleaning the bath and shower. Divert the grey water to the sewer if you have a family member with a "funny tummy" and never use a fine mist sprayer to irrigate with. Choose a low pressure pump with a sprayer that results in large water droplets. This consideration will prevent your grey water entering your neighbors garden as well as public walkways and storm water drains. As far as expense is concerned a good grey water product, one that does not store water but simply filters and diverts, should cost no more than $400.

Derin (author)2008-06-29

could you use grey water from the balcony? that would be rare but would still be good

Master Yoda (author)Derin2008-12-18

is your picture a penguin from and the game club penguin?

Derin (author)Master Yoda2008-12-18


Derin (author)Derin2009-07-05

it has its own official site though

dove cottage (author)2009-06-25

This is a beautiful setup. Mine works off two trash cans, a hose and gravity. I simply haul my hose to the plants and set the timer on my watch. Our well went dry a year after we bought our home, so we haul in our own water. With a family of 7 we generate a lot of laundry & now we have a nice green landscape with a little bit of work. I do not recommend Borax . I have tested it two times, it will kill the plants. I use bleach occasionally ,so I don't worry about it. If it was regular I wouldn't dump it on your plants though.

boarder2k7 (author)2008-10-22

It seems like putting soapy water into the garden is going to have a detrimental impact on plant growth.

ausisit (author)boarder2k72009-06-24

no in fact it will help as when you buy wetta soil and other wetting agents they contain similar materials and the soapy water is good to get rid of aphids

Dru77 (author)boarder2k72008-11-25

Actually, the soap (phosphate or otherwise) is a great fertilizer for your lawn or garden. You have to make sure you switch to organic soaps, use NO bleach or powdered detergents (which contain heavy salts) in order to use this system. But liquid detergent can be great plant food in a system like this. What you don't want to do is put grey water ON the plants, but water the ground by running the outflow into a shallow pit next to the plants, which is filled with bark, stones or other porous materials.

boarder2k7 (author)Dru772008-11-25

Alright yeah that makes sense, because I was thinking of the ramifications of putting all laundry water on the plants, and it didn't seem like it would be good. I guess you could add some sort of a bypass valve to the system to go into the regular sewer/septic system when you needed to use bleach or something in the load.

lilykoart (author)2009-04-07

Great Idea! i was looking into rainbarrels, but saving waste water especially from my washer is also a good way to get "free" water. i use a biodegradable detergent, plus borax powder, and a bit of vinegar in the bleach dispenser. wonder if borax would be ok for the plants? btw, borax is an ingredient used in the most effective ant killer...

ausisit (author)lilykoart2009-06-24

Both borax and vinegar are good to help keep the ph adjusted. The Boron in the borax will help with the roots and any fruit growing on the plants

ausisit (author)2007-10-04

This is a great idea as the politicians restrict the water be used the water going up to form rain reduces so there fore less rain. I am going to use this idea it rocks.

Now if you put some sponge rox in your filter as directed at ausis sponge rox page you would be helping the environment greatly.

Reducing heavy metal bioaccumulation we understand is a big phrase to digest however it is described simply as follows: Heavy metal bioaccumulation such as in large fish they build up toxic levels of mercury which we all know is poisonous, our sponge rox help in reducing heavy metal bioaccumulation by trapping these poisons FOREVER...

lilykoart (author)ausisit2009-04-07

Detoxamin the heavy metals out. google Detoxamin :)

oakironworker (author)lilykoart2009-06-22

Chelation = snake oil =stupid = detoxamin

RadBear (author)2007-09-28

I have three questiions. 1) Can you give us more info on your filter? 2) Does the detergent harm the plants or degrade the quality of the soil? 3) for electronically challenged folks such as myself is there a off the shelf pump controller available? Excellent idea, great executuion and a very good instructable!!!

Drew-Oz (author)RadBear2007-10-01

I've only just found this instructable and am reading the responses first, so this might be covered in the text, but...

Easy solutions..?

Laundry detergents generally contain things that gardens don't like in big quantities, such as salt and phosphorous, so best just to buy detergents that are formulated specifically for grey water systems. Here in Aus, there are an increasing number of brands that produce such a product, and it would appear the market is growing. If your supermarket doesn't stock these, maybe you could buy online. So detergent worries could be easily sorted when you buy. Hand soap or shower products (shampoos etc) are a little more tricky, so be cautious about using your shower/hand basin water too.

Pumps are used in the boating industry a lot, especially water-level-triggered bilge pumps. They're almost always 12V so should be easy to hook up to a common, or garden variety, mains transformer. Now unfortunately, as soon as you attach the word "boat" to any product, you can almost double the price, so you'll have to shop around, but there are loads of different models and capacities available. Why not Google it?

Web references:
There is a gardening programme that has been airing in Aus for years. They publish "fact sheets" about all sorts of things:

Check out these guys too:

Heck! Why not just Google "grey water"...?

smokehill (author)Drew-Oz2007-10-25

Boat bilge pumps are one of those tools that you keep find more uses for. I've used Rule (brand) pumps from online suppliers (cheap) for everything from basement sump pumps to watering saplings in remote locations, spraying, etc. My first $15 pump (no auto shutoff) served as a garden sprayer, running off my 12v tractor btry, for almost 10 yrs -- until I drove over it. I think the auto shutoff for their 350 model (350 gpm with no lift) is another 12 bucks. I use another for the homemade rock waterfall in my front yard. They have a built-in filter that's easy to clean, but if there's a lot of crud in yr gray water it might be best to rig up some pre-filter to save constant fiddling with it. Usually you can find better prices for their hosing if you buy sump pump hose instead of from the boat yard; adding "boat" in front of something really does multiply the price, usually. One of my neighbors whose well went dry for six months used one of these (bigger model, 1000gpm) to fill water barrels from the river every evening, to water his livestock (and himself). I'd do an instructable on the big rock waterfall (total price $45), but am too lazy to take it all apart. Basically two 7-dollar mortar tubs, the pump & a 12v supply, and a scrap of old garden hose. Plus the rocks to hide it all. Anyone could figure it out, tho. The advantage of the boat pump in this application is that you can easily change the water level it kicks on at by just hanging the pump at different levels in the container, since it operates electronically by sensing when it's sitting in water -- thereby not having to muck about with moving floats that hang up, etc. -- and cheap toggle switches can be easily rigged up for different uses. I also feel better with only 12v going into wet environments, rather than 110v. Call me chicken .... Bilge pumps should be listed right along with duct tape & baling wire -- essential for the survival of mankind.

Culturedropout (author)smokehill2009-04-23

These guys have a pretty good selection of various kinds of AC and DC pumps at decent prices. I shop there a lot because they're local, but they mainly do business via web and mail orders.

2 stroke (author)smokehill2009-04-17

I also feel better with 12 volt going in wet environments

Derin (author)smokehill2008-06-29

chicken(you asked for me to call you chicken)

Hawaii00000 (author)Drew-Oz2007-10-29

Yep, the drought has really changed peoples lives in Australia (and i guess its for the better). When I went back a few months ago I was amazed at how water-conscious everyone has become. I think you Yankees could learn a lesson from us

Hawaii00000 (author)Hawaii000002007-10-29

Aussies RULE

Noodle93 (author)Hawaii000002008-01-15

Yeah but we're so freaking far away from anything except Asia and New Zealand.

DonQuijote (author)2007-09-28

excuse me if i misunderstood, 'cause I'm in a hurry right now, but, you ARE using the waste water of your washing machine to water your garden.. right? is that not harmful to the plants, considering the detergent you use for washing?

shwa (author)DonQuijote2007-09-28

if you use gray water for plant irrigation,just be sure to use biodegradable detergents no sodium and no softeners,your best bet is to use it on the trees and shrubs,and not on the plants you eat directly like lettuce or legumes.Yeah I would like to know more about the filter.

slemke (author)shwa2007-09-28

Yes I use biodegradable detergent and now only use either cold water or warm water in the washing machine. Definitely no hot water (I could put a temp sensor in the bin to prevent the pump from working if the water's too hot).

The plants seem to be growing better with the gray water. I also use a lot of mulch around the plants to stop evaporation. As the water is delivered underground via seepage you can water the vegetable garden. If you where delivering the water above ground, this wouldn't be a good idea as the waste water could sit on the leaves etc. After all you put manure in your soil.

The filter is made from plastic fly screen material normally found on windows (to keep insects out). I sewed the screen material so it forms a bag. The opening of the bag is mounted on a 6" circular aluminum frame. The filter doesn't filter chemicals rather it stops lint from clogging up the tubes and pump. The cleaning sensor is a float that moves up and operates a switch when the filter gets so clogged with lint that the water overflows over the top of the filter. Note you have to mount the sensor and the top of the filter above the high water level to prevent false triggering.

The float switches I purchased are from a company in Australia called Jaycar . The vertical float switch for the filter is from Altronics

Hope this info has answered most question.

boocat (author)slemke2007-10-04

You're idea is marvelous! Thanks so much. I can't believe this never occurred to me. I can easily set something up from the washer water line. Terrific.

herebus (author)boocat2009-03-23

I just read an article from ReNew (Aust), the research from this suggests not to use hard soap (cake soap), as it has to much salt (sodium) which can impact on the soil structure, however body wash is OK, so is shampoo and conditioner.

xlioilx (author)DonQuijote2007-09-29

I've personally used detergents in hydroponic systems (not that its the best thing to use) the plants love the stuff just use unscented

misty_bishop (author)DonQuijote2007-09-29

I have been using wash water for this past summer to water my pumpkins, they, and the surrounding plants ( peas that I forgot I planted last year! ) are doing just fine. I just move my hose somewhere else when I want to bleach something, I don't use any special detergent. If I am not mistaken, detergents don't contain phos. anymore.

plzspoilme25 (author)2009-01-27

love it but way to complicated for me to, how much for u to build me one, LOL

nedfunnell (author)2007-10-05

What the hell are you talking about? Please don't post when drunk.

mensmaximus (author)nedfunnell2007-10-05

Dah, I go to many public meetings and city council meetings. Take me on. LOL. Wake up before you post and Google what I said.

smokehill (author)mensmaximus2007-10-25

A truly appropriate response would only get me banned.

Koolraap (author)smokehill2008-03-28

i'm totally with you my man

smokehill (author)Koolraap2008-03-29

I long ago gave up arguing with those half-educated eco-geeks who slept through their high-school science classes. Like their attention span, life is too short. I suspect "mensmaximus" (rather an amusing screen name, considering its Latin translation) waxes ecstatic over electric cars, pretending that electricity grows on trees and does not pollute the air. Ironically, the only electric power that is close to non-polluting is nuclear-generated ... that nasty source that the eco-freaks have been opposing adamantly for decades. Sometimes, no matter how "nice" and apolitical one tries to be, some people just can't pass up the opportunity to inject their political weirdness into their comments.

Drew-Oz (author)smokehill2008-06-29

Er...the mining and processing of uranium ore into just the yellow cake stage alone generates similar levels of carbon emissions as that of a regular coal burning power station would (when compared to the electricity that can be generated by the uranium ore that is mined). So even from the beginning of the process, nuclear power is already running at a carbon deficit.

And then the yellow cake has to be transported (usually around the world) to be further processed into fuel rods, and then transported again to the power stations. Then once the fuel rods are spent, they have to be transported again to a "waste disposal" site (often around the world once more). So think about all those emissions.

And then nuclear waste just sits there waiting to cause who knows what sort of environmental damage in the future (afterall, the waste disposal sites have to be geologically stable for a few thousand years to be safe). Do you know what will happen in 500 years time? 1000 years time? No-one does: nuclear waste is a time bomb in in so many ways.

Oh, and don't think that all this processing, transportation and waste storage is done for free. It's all highly specialized so it all comes with a highly specialized price tag too. Nuclear power generation is frighteningly expensive and so it has to be subsidized by governments (ie our taxes) just to keep it going. Nuclear power stations run at a loss. A BIG loss. So instead of more of our tax money going into useful things like schools, hospitals, public transport, renewable energy etc, it goes toward propping up a financially unsustainable business model that in the real world would have died 50 years ago.

Oh, and then there is the overpriced cost of construction of the power plant as well (being specialized as it is), and then once it's de-commissioned, the entire site is a no-go zone for decades. Once-valuable land just sitting there doing nothing.

So sure, the point-of-generation of electricity in a nuclear power station has less emissions than anything else, but mate, you have to look at the whole picture - and they don't teach that in high-school science class.

I dislike the use of fossil fuels as much as the next person, but for the time being, they're what we have to deal with and nuclear is not the answer - it's part of the problem.

TheMadScientist (author)Drew-Oz2008-10-26

i'm with the next guy, that's REALLY wrong.

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