Simple Grey Water Filter Please?

a bag filter should do it. You just want to take the hair & crud out I suppose.

Sand filtering is inexpensive. It can be made with coarse enough sand to allow flow and still catch larger particles. As simple as a five gallon bucket for a housing.

Your cheapest option would be a sand filter. It could be a gravity sand filter where you water will slowly filter through a bed of sand ( different layers of sand of different grading with coarse sand at bottom & fine sand at top) also known as a trickle filter or else a pressure sand filter where sand of different sizes mixed in a pressure vessel.

Exact method depends on required flow rate, available space, qulaity of water etc.

Sometimes pre treatment to settle larger particles through flocculation/precipitation may be required which will bring down the filter maintenace.

If you want to go one step further and remove all organic or toxic matter to be removed from water you may add on an activated carbon filter.

Just a thought , wouldn't it be better to have the course sand at the top to catch the large particles first? Otherwise everything will be caught on the surface forming a crust, and the rest of the filter media will be wasted. I used a fiber furnace filter over the top of a metal garbage can to strain my washing machine water, with a garden hose attached to the bottom. Just moved the hose to a different tree every load. Worked great.

I was going to mention that too. But I'm wrong so very, very often.

cr3

Typically top layer is the one which does the filtration and botton layer supports filter media in top layer. Once in a while top layer of sand is skimmed off and fresh layer put in. This is typical of slow sand filters.(Ref Wasterwater Engg treatment & reuse by Metcalf & Eddy Page 1074)

If the coarse layer is at top you have to find a way of backwashing the filter which is not going to be easy. Alternative then will be to throw away the entire media which again will not be an easy task.

Anyway slow sand filter are too capital intensive for domestic filtration and therfore a pressure sand filter will be more preferable.

Look around for an old pool filter it has larger in and output lines and is used for large quantities of water and should work well as a gravity fed unit. the older ones use sand as the main filter and you can add diatomaceous earth to refine the filtering a Lil. All easy to find sand hardware store ... dia earth same probably, or pool store.

I agree, use of an old swimming pool sand filter should be the most cost effective method for cleanup . Even new, these units are not too expensive.

Here's a blog entry w/more background on the use of grey water.

A sand filter is over kill for water going into gardens & landscaping. The only reason to do any storage or manipulation is so the water can be applied in more locations @ will, other than that just plumb the shower drain, kitchen sink, washing machine...... out into the closest lanscaping & save the time, effort & $.

some governments frown on such things, so be discreet whatever your solution

Sand filters are good. Depending on what you want to remove, even a simple piece of cloth stretched over a bucket might be enough.

Something to consider when designing a filter is the pollutant you are removing. Grey water from showers is going to have a high concentration of soap. Soap will react with calcium in the water and encapsulate and bind the sand particles, unless degraded. Additionally, it will present a problem then for back washing as snad particles will want to coagulate together to form larger flocs. The easiest thing would be to bacteriologically degrade the soaps on a simple trickling filter, then remove the particulates on a mixed media filter of sand and activated carbon (or just sand if you want). Of course the trickling filter only will work as long as the bacteria on the media are kept alive. Plan on a method to backwash the mixed media filter and dispose of the backwash water.

The simplest option for filtering grey water runoff OUTSIDE is laying a thin layer of soil over the runoff and innoculating it with a hearty mushroom species like russala.

The water will emerge from the other side of the bed almost crystal clear-near potable.An excellent organic/enviro-friendly solution.

see Stamets "Mycelium Running","The Mushroom Cultivator", "Growing Gourmet and Medicinal Mushrooms" exellent books.

Indoors would be a different story.

good point bout the soap ...... but i still think a pool filter would be the best ... mostly cause it was my idea ........... hmm ... so much for humble huh.

Gr8! I like stubborn people!! Because I am also one of them. Until proven wrong logically, I try to stick to my idea.

But how many old swimming pool filters are avavilable around the world! In my part of the word even swimming pools are very scarce. (of course except plenty of rivers and lakes)

And also what is the principle of operation in swimming pool filters anyway.

Older pool filters are basically just vats of sand to filter out larger particles. You can add Diatomaceous earth to get make for a finer filter and it is designed to be "back-flushed" to clear it. Gets things like dust, dirt, bugs, leaves, hair, etc..

When I was studying xeriscaping (which apparently is a trademarked term), I ran across an article on a man in Southern California who had developed a series of cleansers for use in gray water recycling applications. These were bio-degradable, non-toxic, and even had a fertilizer rating.

I'd go for whatever is simple, because this will be most likely to continue to work. Biological processes are what I would trust, beyond the good suggestion of pre-filtering to remove scum and hair.

JMM

Thanks who was he?

Kind Regards

Martin

Martin--

I don't remember his name, sorry. I read it in a book from the local library, which was discussing different people's approaches to landscaping without lawns.

I did a quick Google search on some appropriate terms and came up with an interesting 'blog site:

do-it-yourself.tribe.net/thread/59b4f0bb-a3da-4e91-87d5-031a145997ea - 102k -

Regards--JMM

I haven't read the whole thread so forgive me if I am making a repeat suggestion.

Try a clean floor buffing pad. Some folks use them for home brew goldfish pond filters.

For simply removing hair, lint and standard bits of rubbish that goes down the waste pipe from your hand basin, laundry trough, shower and bath. The filter housing can be a (IE)100 litre plastic drum with the grey water inlet 100mm below the top and outlet on the opposite side 200mm below the top. The filter medium is a tappered wire frame bucket wrapped with plastic fly wire, it depends on how fine you want to filter, you can use a coarse cloth for instance. The finer the filter the more you have to clean it. The wire frame bucket should fit snugly into the filter housing with the top rim, the top rim should be situated between the inlet and outlet levels (IE 150mm from the top of the housing. The wire bucket can be lifted out emptied, washed clean and put back. This is a basic bucket trap and I'm shure there are drawings on the net for a visual.

All the best, Cuemaster

Great site; fascinating thread. Anyone have ideas on this: I want to dispose of graywater from my RV when I don't have a dump station nearby. I collect gray water in a tank, and am thinking if I can pump it out through some kind of filter I can wash the RV with it, or just pump it on to the ground gradually. Since it's an RV, the system needs to be small, and only handle a tiny flow rate, say about 10 gal/day. I used to have a pool--sand filters require backwashing which requires switches and plumbing and a way to expell the backwash water. A diatomaceous earth filter doesn't require backwashing so seems simpler. They make these for aquariums in small sizes. Does passing through one of these make graywater clean enough to safely discharge on the ground or say wash the RV with? I've also been reading about filtering through soil. At 10 gallons a day, perhaps a few potted plants would do the job! This might solve another social problem--even if my system is totally safe for the environment, people will question strange flows or drips of water coming from the RV. But a drip or slow seep into some plants with runoff out the bottom would be nearly invisible one, and even if inspected, innocent looking enough. I probably need some kind of filter to catch hairs and such to protect the pump. Any ideas?

Got to agree with GARTH in that a Sand filter is overkill and you definitely do NOT want to use a Dia. Earth or Activated Carbon set-up as these will just add a high maintenance factor to the equation and will remove the very particulates you are trying to disburse... A Coffer dam will be quite adequate and a prescreen from a Pool Pump will remove the Lint and Hair, etc The residual Soap and "Grey" water will actually provde a measure of insecticide for your Shrubs and Landscaping...

Regards, Kiwi Thompson (15 years environmental Engineering with extensive H2O treatment expertise)

interesting....what about soapy water going into a pond?