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Re-using grey water with a hose and a siphon - bath system.

FireFire Posts: 18,144
edited April 2021 in Tools and techniques

For the last six years or so I have been running an old hose from my bathroom (first floor) to the flower beds.

When not in use, I hang the hose/siphon from a hook outside the bathroom window. The hose then runs down behind the guttering and behind raised beds. It is permanently placed under big bushes. I can then reuse bath water or collected shower water in the tub. I put the hose into the tub with a little siphon/hand pump attached (£5 on Ebay).  I squeeze the hand pump about eight times to get the air out and the water in, and then the water runs out through the hose on its own until the water is gone. Once things are running, I can then go down to the garden and move the hose outlet about, if I need to.

This system works well for me because the a) bathroom looks out right over the garden b) the bathroom is much higher than the garden so the forces clear the bath c) the window is right by the bath so it's simple to unhook the siphon and pop it in the bath without mess or leaks.

NB. The siphon pipe does need to be close to vertical for it work properly. 
As long as the hose outlet is lower than the water source, physics will clear the bath etc for you. The hose can go below the level of the flower beds and up again.

It works wonderfully well for me and feels like a great, practical use of grey water. It's not a good idea to store grey water. There is ecoli etc in the water which gets stinky quickly. But it's fine on flower beds, if it's 'fresh'. Just put in the bath plug to collect shower water. The water pressure for me is good because the source is on the first floor. It would work just as well with a bucket or a sink.

You can run washing machine outlet pipes/hose out onto beds. Best to use eco/gentle soaps. Best not to run dishwashers this way as the use softeners/salt which is bad for plants. In both cases the machines would need to be at a point higher than the garden if you are using pure physics to empty the machines. (A sunken kitchen below the garden, like mine, wouldn't work).

I hope the detail might prove useful to you as ideas for reusing water.


*Siphon, hung on the knob to keep it vertical.

Hooks where the hose and siphon pipe hang when not in use. The hose is tied in permanently behind the guttering, which disguises it. Kind of.

*The (green) hose runs behind the planters on the left and the outlet sits under rose bushes. I can then come down and move the hose end about, once the water flow is going, if needed.



  • LoxleyLoxley Posts: 5,565
    I've thought about doing this many times, thanks for sharing.
  • FireFire Posts: 18,144
    edited June 2021
    I use this all summer long, re-using all bath and shower water on the garden.
  • KeenOnGreenKeenOnGreen Posts: 1,824
    @fire Your post made me laugh.  We used to do exactly that in our old house, and felt like the neighbours must have thought we were mad!  As we are in a bungalow now, with a garden that tiers up above the house, sadly we can no longer use this method.

    We did at one point sit a bucket between our legs in the shower, to catch any excess water, but quickly came to the conclusion that that was really silly.  
  • FireFire Posts: 18,144
    @KeenOnGreen yes, the physics have to be right for this to work - the source has to be above the destination.

    From the first week I moved in, the neighbours were sure I was quite mad, so it was good to get that out of the way. Onwards and upwards! :D
  • Lizzie27Lizzie27 Posts: 11,999
    We tried that method in our old house when there was a drought one year as the bathroom was above the garden but it wasn't very successful (we didn't have a proper siphon). Unfortunately we can't do that here as we have same set up as KeenonGreen but I do use a washing up bowl in the sink and fling used water on the garden.
    North East Somerset - Clay soil over limestone
  • Nanny BeachNanny Beach Posts: 8,669
    We live in a bungalow, hubby was thinking of installing a pump,but it's expensive and not that simple,my conservatory is over the back,then a big patio,a long way to go
  • bertrand-mabelbertrand-mabel Posts: 2,594
    As a child I thought everybody had a grey water butt in their garden. This would take the water from the bath and sink (no showers then) directly into this huge water butt. This water was then used for the garden produce. I am talking over 50 years ago!!!
    Imagine my surprise when I found that we were unusual.
    Can't do the same here as our cottage doesn't have upstairs bathrooms but we use rain from all available surfaces to be gathered in our many water butts around our property.
  • DitsyDitsy Posts: 196
    edited June 2021
    Very resourceful @Fire. :)
  • FireFire Posts: 18,144
    It's a dodgy to keep grey water in a water butt (rather than just using a hose direct) as trace human bacteria in the water, such as ecoli, can build up, smell and pose health worries.
  • FireFire Posts: 18,144
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