Grey water to flush toilet.

[Frank C]

Anyone modified their Ollie to use grey water to flush the toilet?  I’ve seen this on a few RV forums as a way to avoid wasting precious fresh water from the fresh water tank to flush the toilet.  The attached link is a video showing the mod.  Plenty of room under the forward dinette seat of the Ollie to run a PEX line from the grey tank, mount a separate filter & pump for the grey water and access there to run a PEX line to the toilet.  Would install the pump switch on the inside partition wall next to the toilet.  Considering this project (and before anyone says it, NO, I don’t want to install a composting toilet).   Have to think through some of the details yet though.  Would have to add a valve system if I still wanted the option to flush from city water when available, and I’m sure there are other details haven’t thought of yet.  

https://www.rvrepairclub.com/video/rv-grey-water-system-101-and-benefits-of-recycling-kit-007916/

 

 

[John E Davies]

That sounds like a winner for anybody who wants to retain a flush toilet. How often would you have to change the filter element, and what is that cost? Are you planning to do the work yourself? The only tricky part IMHO would be drilling the hole in the grey water tank and installing a PEX fitting for the pump supply line. Have you  located a suitable place for that, one that has good access for a drill? The big black waste pipe is blocking it all along that left side of the cabin. I hope you will post pictures. It sounds like an interesting mod. About how much water is used by the toilet per person per day?

John Davies

Spokane WA

[SeaDawg]

Our sailboat sends handwash water from the sink, to the toilet.  It's ok ; but we always have to educate new users. It does save water. But, can overflow, if uninitiated don't comprehend the system. 

A successful grey water recycling system, imo, requires many filters, and a separate tank. And there's a lot of room for error, imo. 

We spent extensive time on this concept, building our leed platinum home. Hair, soap,  kitchen sink debris, etc., just didn't make sense to make it worth the extra plumbing, tanks, and filtering. And, history has shown many issues with grey water recycling.  

We opted for extra low flow faucets and toilets. (Toilets are the big siphons of clean water, honestly. We opt for if it's yellow let it mellow. Brown, flush it down, plus the lowest flush toilets we could buy.)

There are many ways to skin the water conservation cat. If the grey water recycling works for you, I'd love to see how you accomplish it. 

[Frank C]

4 minutes ago, SeaDawg said:

Our sailboat sends handwash water from the sink, to the toilet.  It's ok ; but we always have to educate new users. It does save water. But, can overflow, if uninitiated don't comprehend the system. 

A successful grey water recycling system, imo, requires many filters, and a separate tank. And there's a lot of room for error, imo. 

We spent extensive time on this concept, building our leed platinum home. Hair, soap,  kitchen sink debris, etc., just didn't make sense to make it worth the extra plumbing, tanks, and filtering. And, history has shown many issues with grey water recycling.  

We opted for extra low flow faucets and toilets. (Toilets are the big siphons of clean water, honestly. We opt for if it's yellow let it mellow. Brown, flush it down)

There are many ways to skin the water conservation cat. If the grey water recycling works for you, I'd love to see how you accomplish it. 

Thanks!  That’s the kind of input I was looking for to help in the go/no-go decision on this project.   I do have extra screens added on all of the sink and shower drains to keep as much debris as possible out of the grey tank, and we are careful to not any put cooking grease, etc. down the kitchen sink drain, but soap residue & fine food particles could still be an issue.  So that brings up another modification, anyone modified the black tank flush line to add a tee to that line to do a grey tank flush?  🙂. This potential grey water project seems to be expanding in scope and budget. 😂

[SeaDawg]

Modifying the line from the bath sink  to the toilet would probably be pretty simple, imo. 

We brush teeth outside, whenever possible.  So, it's just water and liquid soap. 

Like I said,  still an education issue. And, something to be acutely aware of. 

Our bath faucet is limited to (I think) .25 gpm or .5 gpm. I don't remember.  In the house, all bath vanities are .25 gpm. 

[John E Davies]

Here is your plumbing diagram. 

 

I don’t see any easy access location to add a fitting at the bottom edge of the grey tank. It is pretty much obscured everywhere by other parts.

John Davies

Spokane WA

[SeaDawg]

I agree, @John E Davies. 

Go for the simplest way.

Definitely needs a lot of thought.