DIY Grey water toilet feed.

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by nfored, May 18, 2011.

  1. nfored

    nfored New Member

    Messages:
    10
    Location:
    Kansas City
    Would it be possible to have an electronic float valve installed in the back of a toilet?

    I run a drip system to supply constant water changes to about 1000 Gallons of aquariums. And before we have a repeat the drip line is about 6" above any possible water line. I drip close to 150 Gallons a day, which means I also drain 150 gallons of water a day.

    I was draining this to the yard and plants, but as the water company refuses to give me a break on sewer usage for this water that never goes into the sewer I have decided I need to figure another way to save money on water.


    So my thought was to have a 150 gallon water storage tank in the basement. The water draining from the fish tank would enter the top of the storage tank again from 6" above any possible water line. I would then have a drain at the top of the storage tank hard plumbed to the houses main drainage system. My thought was to have a pump in this tank that was controlled by the float switch in the toilet.

    I have two potential problem I wanted advice on.

    1:
    The electronic float switch, has anyone seen them in use and what are my risk of switch failure introducing current in to the toilet?

    2:
    Normally I would say I don't use 150 gallons a day in toilet water so the excess each day would drain away. But on chili night or what ever and I happen to use more then that I need a way to introduce water into the system. I would love to connect a float valve to the storage container and connect it to the houses water supply, but then there is a risk of back siphon if they shut off my water. So this only leaves me with yet another electronic float switch inside the storage container, that this time connects to a solenoid that turns on or off the clean water that would enter the storage tank form 6" above.


    Also if you can think of any other ways to use this water I am all ears.
  2. jimbo

    jimbo Plumber

    Messages:
    8,997
    Location:
    San Diego
    Since the toilet uses 1.6 gallons per flush, and if on the far end you flushed 20 times a day, that is 32 gallons. Around here, our water is fairly expensive, and works out to about 1 cent per gallon. Sounds like an awful lot of work and expense to save 32 cents a day, or about $10 per month.

    You would not want that water in your toilet tank...I suspect things would grow!
  3. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,060
    Location:
    Cave Creek, Arizona
    It doesn't appear you will save much as far as money is concerned. You will still have to pay for the 150 gallons of water every day, and therefore the sewer charges will be exactly the same, you will just be using the sewer for the water. You will save a small amount for the water you would have used for the toilet, but unless you have a serious issue you probably do not flush the toilet very often. Do NOT interconnect that water with your domestic system without serious backflow/back siphonage protection. I do not see any benefits to YOU by making changes, and few to the environment since that water is being "recycled" into the water table.
    Last edited: May 19, 2011
  4. nfored

    nfored New Member

    Messages:
    10
    Location:
    Kansas City
    I did't know it only used 1.6 gallons? sounds like one of those new toilets but if thats true your right its not that much savings but its some that's what I also asked if you had other ideas to reuse this water.

    Also why is it every single time I ask a question someone keeps talking about a back siphon, the first time I was told this forum assumed this because I didn't give details.

    So this time I explained clearly and clearly said that all water that is contaminated is introduced from 6" above any possible water line? I am seriously confused this time as you could hear from my outline there is no possible back siphon even if the water was shut off by the city unexpected. Please if you can see in my design how it could happen please tell me so I can be safe.

    Thanks for you're opinion and I agree it does sound like its not worth the cost of the electronic float switches. But just for my knowledge what do you think about the float switch and the possible failure causing current to be brought into the toilet.


    HJ I can see it was you that made the assumption last also about the back siphon, I am interested to you the reason why you think it could happen this time in this design.
    Last edited: May 19, 2011
  5. Redwood

    Redwood Master Plumber

    Messages:
    7,450
    Location:
    Connecticut
    Because what you are proposing is a BackFlow waiting to happen...

    Read Here... http://www.watts.com/pages/learnAbout/usc_study.asp?catId=65
  6. Terry

    Terry Administrator Staff Member

    Messages:
    15,316
    Location:
    Bothell, Washington
    The UPC also allows for reclaimed water for flushing water closets and urinals and supplying trap primers.

    Any Reclaimed Water System has to be entirely separate from the potable water system.
    There can't be a "connection" between the two. And the Reclaimed water pipes need to be marked as such. Otherwise, this is a clear code issue and it's illegal.

    Reclaimed water is water which, as a result of tertiary treatment of domestic wastewater by a public agency, is suitable for controlled use. The controlled use can be the supply of reclaimed water-to-water closets, urinals and trap seal primers for floor drains and floor sinks. In areas under the jurisdiction of the UPC this system is usually called a “purple pipe” system because the reclaimed water is conveyed in pipe that is purple.
    Last edited: May 19, 2011
  7. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,273
    Location:
    New England
    It's been quite awhile since the low-flow toilet requirements were imposed, but if you have really old toilets, they could use as much as 5-7 gallons to flush.

    I think I'd consider a cistern for the runoff, and then use it to water the lawn when the need arose rather than a convoluted system to try to save a little with the toilets. Using gravity to feed the toilet would mean some valves just won't work, and if they did, they'd take a very long time to refill. Adding pumps would negate any savings with the install costs and running costs. Do you like water features? You might put a pond and maybe waterfall in the yard, refilled by the overflow. These can be really relaxing, and in the case of a pond, the plants could keep the water quality up.
  8. nfored

    nfored New Member

    Messages:
    10
    Location:
    Kansas City
    Please tell me how the back flow can happen, so I can be safe like I asked.

    as far as I know since the water in is 6" above the water line a siphon or back flow could never happen. And the the only place where clean water is proposed in my setup was in case of over usage and I said it would also be 6" above and controlled by a solenoid.

    You keep saying things without actually helping.


    So if back flow is possible tell me where in the design and suggest a way to fix it. As far as I know the only place it could happen is inside the tank on the toilet which is contanminated any ways, and only from their connects back to the sewer.
  9. nfored

    nfored New Member

    Messages:
    10
    Location:
    Kansas City
    Thanks the toilet would be above and feed by a pump. I will also take you advise and use a second pump for watering plants and the yard. Because of the large amount of fish tanks I have a lot of pumps so the start up cost would be little, but your are correct I would need to think about electrical cost in pumping from the basement up to the tank a high head means high wattage. I have been trying to talk the wife into a pond, but if the pond has fish your doing more harm by dumping old fish water from tanks into the pond. As nitrates build up quickly and can cause huge algae problems or fish health issues.

    I might just have to admit that there is no way to use this water for anything other then watering plants which is a great way to get fast growing plants.



    Side not Terry did you ever get your shopping cart installed?
  10. jimbo

    jimbo Plumber

    Messages:
    8,997
    Location:
    San Diego
    If it is of any concern to you, it would not be code legal to use that fishwater in any way inside your house. The reclaimed water Terry mentioned is just that....purple pipe water which has been to a treament plant, and then is sent back out for use on landscape, etc. There was a MAJOR issue recently in San Diego. A plumbing contractor inadvertently connected a building supply to a purple pipe. Lot of people got sick. Purple water is not potable.
  11. nfored

    nfored New Member

    Messages:
    10
    Location:
    Kansas City
    It is of concern to me, and I think you for pointing that out. However just as a normal person trying to get advise from people that know what they are doing this site is not friendly.

    That aside from the very valid pont of no real savings is enough for me to not due this. I honestly have never been on a forum where the responses are like this.

    Everyone keeps menitoning back siphon but no one is willing to point out where it could happen.
  12. Jerome2877

    Jerome2877 In the Trades

    Messages:
    397
    Location:
    BC
    The reason for this is saftey. People have died from backflow into the potable water system so we take it very seriosly! What you are suggesting is considered an air gap and is one form of backflow prevention. However this would still be a potential cross connection. Lets say for some reason your system stops pumping water to the toilet so you (or someone else) decides to connect the toilet back up to the ptable supply. Now you have a cross connection. Your AHJ would require an RP backflow preventer (more than likley at your cost) if they knew about your plan.
  13. cacher_chick

    cacher_chick Test, Don't Guess!

    Messages:
    3,260
    Location:
    Land of Cheese
    If you really want to do it, you could run an entirely separate non-potable water line to the toilet and to an outside spigot, disconnecting the existing toilet supply line. Drain the aquarium water into a basin which has a pump controlled by a pressure switch that feeds a bladder tank connected to the non-potable water system.

    Basically the system would work like a common water well, but using the basin as storage.
    Last edited: May 19, 2011
  14. nfored

    nfored New Member

    Messages:
    10
    Location:
    Kansas City
    I don't think I will due to the many valid ponits of it not being worth the effort.


    Thank you so much for actually saying how back flow can happen. I could defiantly see that as a possibility. If you had to go and the pump stopped you might not stop to think about the what ifs and just think about how to get it going right now.

    I will just have to accept the 55.00/month in additional water usage as the price to pay for so many tanks.
  15. Terry

    Terry Administrator Staff Member

    Messages:
    15,316
    Location:
    Bothell, Washington
    Have you installed Watersense toilets yet?
    Just doing that saves a lot of water.
  16. nfored

    nfored New Member

    Messages:
    10
    Location:
    Kansas City
    No but thats a good point. Maybe I am looking at this backwards. Maybe I should be looking at ways to reduce water usage else where rather then reusing water. I have installed 3 and 2.5 gpm faucets every where, I have no idea how to tell if my toilets are water friendly. I will take a look at these water sense toilets.

    My wife hates how I do dishes.
    I put like 2 inchs of water and soap in the sink. Wash a dish and then turn the water on to rinse it, by the time I am done I have a full sink of water. This saves me water compared to filling up the sink to start with and then rinsing.
  17. Jerome2877

    Jerome2877 In the Trades

    Messages:
    397
    Location:
    BC
    What about thinking of rain water collection to supply the fish tanks? Basically divert your roof rain leaders into a large tank, (there are ways of doing this so you avoid getting unwanted debris) then use a pump to supply the fish tanks.
  18. cacher_chick

    cacher_chick Test, Don't Guess!

    Messages:
    3,260
    Location:
    Land of Cheese
    Here the water utility will rent us a meter for metering our garden irrigation so that we can deduct that usage from our sewer bill. If there was a similar program there, you could use it to feed your aquariums.
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