Use gray to flush black
Related to my previous post, has anyone tried some kind of pump to use their gray water to flush a toilet ?
Forum Discussion
- Gray water stinks as bad as black water. I wouldn't want that in my toilet after you flush.
theoldwizard1 wrote:
TakingThe5th wrote:
I have a grey water flushing system installed in my 5th.
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I have a separate pump and filter for the grey side.
Anything "special" about the pump and filter you are using ? Could you share the brand and model numbers ?
The filter I use is a "bowl" filter with an element that is more like a screen then a filter which is good for catching hair and can be cleaned. The pump you will use should almost be equivalent to your own fresh water demand pump but make sure it cannot out-pump the freshwater pump. I have check valves in my system but in any event I do not want the grey water pump to be able to overpower the fresh water pump head to head, just as a further safety precaution. Like the fresh water pump, the grey water pump should be a demand pump.
I can look for model numbers for you tomorrow.TakingThe5th wrote:
I have a grey water flushing system installed in my 5th.
.
.
.
I have a separate pump and filter for the grey side.
Anything "special" about the pump and filter you are using ? Could you share the brand and model numbers ?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. 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.
I have a grey water flushing system installed in my 5th. I have two grey water tanks and I only flush using the shower and bathroom sink water so the water is pretty clean. I can select fresh or gray water for flushing. I have a separate pump and filter for the grey side. Our problem was that the grey shower water tank would fill up 1st while the fresh water tank would become empty 1st. The grey water system creates a perfect tank balance and we are not afraid to use adequate amounts of water for flushing. I use black tank chemicals but put them into the grey tank where they get dispensed over time into the black tank. The system works well and extends our stay by several days.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 !- 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. - 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.
- I'm with mockturtle and use dish water kept in a pitcher in the adjacent shower. I collect some shower water too.
- 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.. - 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
