Grey water - Upstairs waste for downstairs cistern

[Garaged200]

Hi,

We are looking to revamp our upstairs bathroom and downstairs loo and wondered if any systems exist that can use the grey water from upstairs? With gravity on your side i would think something would exist that uses the upstairs grey water and stores it in a 'primary cistern' to use to flush the toilet and then in the event that runs out use a fresh water tank or just feed fresh water into grey water tank to top up/flush the toilet. I was thinking with ball valves closing one from the other etc it should be relatively easy. It means the grey water would be constantly used and not sat for weeks. Are there issues with bio 'horribleness' building up and venting etc?

Any help would be great. We've go plenty of head room and it seems a shame not to use the sink/shower water for flush the toilet.....

 

[kbdiy]

It sounds feasible in theory. However I can see the soap residue becoming a problem before too long as the waste water is likely to sit in the tank/storage vessel for some considerable time before it gets used. Consider the volume of waste water produced against the limited amount used to flush a toilet and you will get the idea.

I don't know about you but I have to periodically flush through my shower and basin wastes to clean out the soapy residue, so I think that might be the stumbling block.

 

[longdogs]

I know its not exactly what you want but you can buy these...

http://reviews.diy.com/2191-en_gb/12127590/reviews.htm

 

[Newboy]

It's worth remembering that water is not the only thing that goes down your basin/shower/bath waste.

Hair/soap/skin and a lot of other stuff it's better not to mention!

If you fancy taking a trap off any of the above fittings and have a look inside - bearing in mind that the trap is washed through with water every time the fitting is used.

 

[kbdiy]

and a lot of other stuff it's better not to mention!

Is that a confession?

 

[Garaged200]

Cheers guys.

I was thinking that the tank could have a filter in it to clean every now and again. As for the soap - it may help move 'things' along

There must be a product out there as it all seems a little to obvious.

 

[Dan Robinson]

There are eye wateringly expensive units available. The name escapes me at the moment, but you won't get change out of £2k.

Bulky too.

 

[boringoldcodger]

I've had a very odd thought.
As I understand it all new flush valves have an in-built overflow (so any o'flow goes visibly into the bowl, not invisibly down a pipe). If the cistern has a hole for an o'flow pipe as well as for water inlet then presumably the (now) unused o'flow hole could be used for a 2nd inlet.
Equilibrium (?) inlet valves such as:
http://www.fluidmasteruk.com/our-products/fill-valves/bottom-entry-fill-valve.html[url]
look as though they're far smaller than ball stop-cock ones, so should allow 2 in a single cistern.
Could you keep the current water supply (possibly with an extra external valve which greatly restricts the flow) and then have a second supply which is from the grey water tank ?

This wouldn't give 100% grey water flushing, but wouldn't need anything complicated and would still allow the cistern to refill when there's no grey water.

A caveat: Link
http://www.aecb.net/forum/index.php?topic=1735.0
[/url]
is about waste water heat recovery but the first reply mentions "putrid smell" from the gunk.

I hasten to add, I haven't tried any of this (I'm OK at thinking about things but totally useless at actually trying them).

Cheers, Graham

 

[Dan Robinson]

You're right. It is an odd thought.



Modern cisterns of only have one orifice too.