Use gray to flush black

[theoldwizard1]

Related to my previous post, has anyone tried some kind of pump to use their gray water to flush a toilet ?

[theoldwizard1]

DrewE wrote:
The question wasn't about using gray water to flush out the black tank, but using it to flush the toilet. I think I've read here of one or two people who have rigged something up to do that. It's basically just installing a suitable pump and running some water lines to it.

Correct ! Clearly some kind of strainer needs to be used to prevent hair, etc from clogging the pump.

DrewE wrote:
Note that the gray water can get pretty stinky over time.

Noted !

[DrewE]

The question wasn't about using gray water to flush out the black tank, but using it to flush the toilet. I think I've read here of one or two people who have rigged something up to do that. It's basically just installing a suitable pump and running some water lines to it. Probably having a selector valve to let either the fresh or gray water be used for flushing (and a check valve for the fresh water line to prevent any possible cross-contamination from the gray water) would be a decent idea in case one needs to go potty before anyone has taken a shower or washed the dishes.

Note that the gray water can get pretty stinky over time. For the amount of fresh water that would be saved, I don't think I would bother. RV toilets don't need a lot of water to flush.

[Dutch_12078]

I have a third "master" valve on the waste water outlet that can be closed while both the black and grey valves are opened, allowing the tanks to act as a single large tank.

[Lwiddis]

I'm with mockturtle and use dish water kept in a pitcher in the adjacent shower. I collect some shower water too.

[downtheroad]

We use a Rubbermaid dish pan to do dishes in the galley...then use this soapy water to flush toilet....but only when our gray tank starts to get full and we aren't on a sewer site...

As with everyone...gray tank fills much faster than the black..

[RLS7201]

I installed a gray water transfer pump. Cut a "T" into the 1½" gray water drain line. Plumbed pump output into the black tank vent stack, about 1' above the tank.

Richard

[profdant139]

When our gray water tank starts to get full, we open the valve and drain some gray water into a bucket and then pour the bucket into the toilet. Both the gray and black tanks are 25 gallon, but we generate about 5 gallons of gray water a day and maybe one or two of black water. So this "bucket brigade" helps extend the time that we can boondock, and it also dilutes the black water.

A pump would be very useful, but I am not sure how to plumb it safely.

[jplante4]

Run the water that you waste to warm up the shower into a bucket and use that. I would use the gray water. I have a clear section of sewer pipe and the first glug of gray water is pretty nasty with solids and coffee grounds.

[mockturtle]

I pour dishwater down the toilet.

[Artum_Snowbird]

I would suggest that you find a flat pan and collect the shower water as you stand in the pan. Some might miss it's mark, but pour that into buckets, maybe through a strainer to collect the hair. There is small lines and valves that water has to flow through, and the use of gray water as a flusher could lead to a lot of problems if something that went into a gray tank gets stuck along it's path, or causes gate valve problems in the toilet.