In-house Gray Water Systems: Simple solutions for water management

Nearly half the water used in the home is flushed down the toilet. There are many solutions for under sink gray water units that help save and recycle usable water. A strong contender among the competition is the AQUS gray water system which efficiently captures the water from the sink and transfers it to the flusher. This handy unit can save up to 7 gallons of water per person each day, that figure adds up real quick.
The trick? The sink water first runs through a simplified dispenser or filter of sorts that houses bromine and chlorine tablets. These tablets kill the bacteria from the polluted sink water. A 5.5 gallon holding tank lies beneath your vanity and is attached to the dispenser. A modified p-trap directs the water from the sink through the dispenser and into the tank.

A small copper or flex tube is directed from the holding tank into the toilet bowl tank to facilitate the transfer of water. A fill-control device attached to the back of the toilet impedes the float valve from filling your toilet with freshwater. Instead, the gray water from the vanity holding tank enter the toilet bowl through two tubes which enter through drilled out bolts that will simply replace the bolts on any standard toilet.
The system is effective, cheap, and easily maintained. I know of two developers in my neck of the woods who have begun installing these in their developments. The cost and labor to install them is cheap compared to the publicity and wow-factor that they claim helps sell them homes in the current tough residential market. In many ways, these kinds of simple and eco-friendly solutions are helping businesses profit while at the same time establishing higher demand for environmental sound alternatives and products.
Most of the units out there run between $200-300. That cost can be regained quickly. For example by simply installing more efficient toilets with low flow flush and a smaller holding tank you can save $100 a year. These toilets use 60 percent less water than the pre-1994 model toilets. If you were to couple low flow toilets with a gray water flush system the saving s could be significant especially considering the inevitable shortages on fresh water that threaten all of us in years to come.

23 responses

  1. this isn’t the first time something like this was introduced. anyone could make one of these with stuff from the hardware store.
    one thing to remember is that graywater has carbon and oils in it that can ultimately interfere with flushing the toilet.
    it’s cool that this is on the market but let’s keep an eye on context.

  2. Actually, there IS a projected shortage of freshwater on the North American continent because we’re depleting the aquifer (natural stores of underground water) that lies under the Midwest faster than rainfall can replenish it. Add to that the amount of water becoming undrinkable due to chemical pesticides and fertilizers seeping into the water table and you have a really scary scenario in the coming years. It’s just common sense.

  3. These residential greywater re-use ideas can be used anywhere people don’t want or cannot afford to flush fresh water down the toilet. Although they don’t address agriculture or industrial water use, they are part of our larger idea of water use. Sucessful projects tend to inspire development in other areas of use. Less residential water use means less expense for regional governments in that area.
    Treatment of potable water is an energy expender for most people in the industrialized world, and whether energy or water is being used more effectively, you’re making an improvement to re-use drinkable water. It’s easy to dismiss this idea in the U.S. where we’re a long way off from feeling the pinch. We have an energy advantage so chances are good we’ll be able to process water for our communities(bearing in mind the water history of states like CA). Other areas of the world are not so lucky. I say, keep testing ideas and wiki your results. People who need these designs can use them. And really, why be a ney-sayer. If people want to invest their time and money in these plans, why be snide? Would you prefer they invest themselves in NASCAR?

  4. GWS- has become one of the most improtant vital features for the hotels , buildings and labor accomodations in the united arab emirates , some areas have no sewage pipe network , thats why they base on this sytem , its effective and makes use of 80% of the used water and this treated water can be used for irrigatiing the plants and the industrial projects
    one of the problems that grey water have , the parameters to be achienved can be hard to be at the desired rate , BOD this parameter may exceed the std range and become hiegher than expected , specially in the labor camps , some companies failed to achieve this parameter and for the water dep – this is not acceptable , they are still searching a solution and they hope the new tech can give the hand
    SALAM ENTERPRISES CO – DUABI is one of the leading companies in this field they have supplied some of the projects and their system passed the test
    grey water sytem can be applied for each house and this will save the water and the env as well , plus it makes it possible to reuse it again , no matter how much the system costs , but how much water it saves

  5. Upon first inspection of the Aqus it seemed to be fairly well thought out. There are a lot of parts that are specialty parts that have been built overseas. During the installation I encountered problems with the rocker device that fits inside the toilet tank. I called Water Saver Tech and got Mark Saunders (the inventor) on the line. After describing the ill fitting part to him, he told me that I probably got a hold of some old stock and promptly sent me a newly designed rocker assembly. A week later, after receiving the new part and assembling the unit I can say that it worked. (sort of). There are electrical points that go inside the toilet tank that are exposed to moisture. These points activate the pump when the water level drops in the toilet tank. They will need regular attention. This design error is exacerbated by the chlorine in the water that causes most metal parts to corrode quickly. This coats the points and causes them to not make a good contact.
    Secondly, the only way that the toilet bowl can fill is if that water comes from the fresh water fill of the toilet. So you are only really saving about 3/4 of a gallon per flush. The fresh water going into the bowl gives the impression that the water entering the tank is fairly clean, but it’s really pretty funky because there is virtually no filtration of the water coming from the sink. This means that your toilet flapper is going to need to be cleaned about once a week.
    The biggest design flaw in this product is the use of 3″ chlorine tablets placed in the drain line to disinfect the sink water as it goes to the storage tank. When the water passes over the chlorine tablets it creates chlorine gas. This chlorine gas comes up through the drain pipe and stings your nostrils pretty good. Since there is no sink trap between the sink and the tank there is nothing to keep the gas from escaping back into the bathroom. That isn’t the biggest danger though. The biggest danger is if someone is cleaning the bathroom and inadvertently pours a cleaner containing a significant amount of ammonia down the sink. Guess what? CHLOROFORM GAS!!! For those of you that aren’t aware of household chemical rules 101, Don’t mix chlorine and ammonia, this is what happens. Chloroform gas is created from the mixture of chlorine bleach and household ammonia. If you inhale modest amounts of chloroform gas you will be rendered unconscious and your breathing passages will be permanently damaged. If you remain in the area you could die, but don’t ever sign up for another marathon race.
    I don’t want to harp on this too much, but the swimming pool chlorine that is sent with this product is designed to be totally submerged under water. i.e. swimming pool chlorine. From what I have read in the EPA regulations for hazardous materials, there are heavy fines and imprisonment for using this type of chlorine for anything other than what it is designed for. (swimming pools). This has to do with the fact that when this product is not totally submerged, it creates large amounts of gas that are intended to be entrained in water, not breathed.
    The product is however useful if you don’t follow the instructions with the chlorine. You will have to pour something like peroxide down the sink every couple of days to kill the lively bacteria and odor that go along with them

  6. DUH.. fresh water is very precious these days. the more we keep using toilets that flush CLEAN water and not recycling the perfectly usable gray water that can be treatd, we’ll eventually run out of water completely. this is a great way to conserve water

  7. We manually collect grey water to flush our toilets with a cost of $0.00. When we shower (showerhead over our bathtubs) we plug the drain then when we finish with our bath/shower we scoop the bath water into 5 gallon buckets which sit in the bathtub. When we need to flush our toilets we place 1 1/2 gallons into a 2 gallon bucket and pour the grey water into the toilet bowl….potty all gone and we have used the water twice. I paint the 5 gallon buckets to match our bathroom and with the shower curtain pulled no one even notices that they are in the bathtub during the day. It is vital to use plastic buckets and a plastic cup/glass for scooping grey water because metal items will scratch your porcelan tubs. It has just become our routine to shower & scoop the water into the buckets so the tub is ready for the next person. This saves on our water bill too.

  8. Question:
    I am attempting to install a grey water system – I have my master bath down to the studs – there is a half bath on the upper floor directly above the master bath – I want to use the great energy of gravity to feed the master toilet with the grey water from the half bath’s sink. Does anyone see an issue – with using the concept shown here but without the pumps? Thanks for your input – some is better than none…. Seaturtle

  9. In response to the question regarding using water from the bathroom on the upper floor to supply the toilet on the lower floor, my view is that it will work. You don’t need to use a pump then.
    My concern with this system is the use of chlorine or other chemicals to disinfect the water. This may create unintended negative environmental effects, as another person stated previously.

  10. shower and scoop sounds like a lot of work. How much time do you spend doing that? How much is your time worth?
    I think the grey water is a fantastic idea. combined with solar panels your bills will be drastically cut.

  11. I’m just about to make a new lid for the toilet tank, with a funnel area that I can pour sink water into collected using a stainless steel mixing bowl just sitting in the actual sink. I can just remove the bowl if I prefer to let something go right down the drain. Most of the water will be the fairly clean stuff collected while waiting for the hot water, as well as hand washing water. Since I don’t own the place I can’t put in anything too permanent. I’m turning off the inlet valve to the toilet, will see if I get enough water to enable flushing from my diverter system. I like the “bucket and chuck it” tub method too, will get that going next. There are all sorts of little hand pumps available that might work for filling the buckets quickly and easily. Dish water is the next problem as this is usually too greasy and full of food residue to use directly.

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