Home: Water: Plumbing
Syphon bath overflow   (+3)  [vote for, against]
Re-use "grey" water in the garden

I put the plug in when I had a shower this morning. I worked out that I used about 40 litres of water. I'm all in favour of reducing water usage but not of smelling like an alligator, so I'm not going to reduce the number of showers I take. What I want to do is to re-use the water. One option is to put it on the garden. We've been using the washing-up water on the garden all year, and the plants don't seem to mind the small amount of soap that this brings.

Naturally this calls for an integrated system - I couldn't just bucket it out, as I'm afflicted with being an engineer.

I don't want the water to go into my water butt every time, so hooking it up to the plughole directly is out. What I propose instead is a bath with the overflow positioned level with the bottom of the bath, then (out of sight inside the bath moulding) going up to the level of a conventional overflow, out through the wall and down to my water butt. A hand pump, elegant in chrome and neatly integrated into the bath between the taps, would allow the syphon to be started.

In the event of a dripping tap while the plug was in, the water level would eventually get high enough that the syphon would start naturally and empty the bath fully, so the proper function of the overflow as a means of preventing the bath overfilling (and trashing the bathroom) would be preserved.
-- david_scothern, Jul 17 2013

We used to do this using the somewhat less elegant method of chucking a length of hosepipe out of the bathroom window.
-- Wrongfellow, Jul 17 2013

Indeed. But I'm afflicted with being an engineer.

Separately, I found a rather neat product in the form of a bath plug with a standard hosepipe fitting integrated into it. The plug stops the water going down the drain (well, surprise!) and the hosepipe fitting gives you a way to keep the end of the hosepipe down in the water while you syphon the water out of the window. Cost a fiver, which seemed reasonable - but I won't link to it, lest I look like I've got some undeclared interest in it...!
-- david_scothern, Jul 17 2013

If you could access the tub's drain pipe, you could in theory put a valve in it, and new pipe from that valve to your desired alternate destination. Then all you need is some means to turn the valve when you don't want the water to go down the sewer line. Perhaps this second device should be spring-loaded, so that the valve doesn't stay in that alternate position.
-- Vernon, Jul 17 2013

What [Vernon] said.
-- 8th of 7, Jul 17 2013

What [Vernon] said is baked. In a version I've seen you twist the plastic grating in the plughole to redirect the water.

The two obvious problems with this idea are that (1) you don't necessarily want the bath to empty completely when you accidentally allow it to overfill, and (2) your bathwater comes in contact with the inside of a potentially gungy pipe.

The obvious alternative solution is to have two plug holes.
-- spidermother, Jul 18 2013

The obvious alternate suggestion is to have two bathrooms.
-- Ling, Jul 19 2013

random, halfbakery