Replacing black water tank with grey water tank

[AnnArborBob]

Here is a video about composting toilets in case anyone is interested:

https://www.youtube.com/watch?v=FS8B..._cv9YN8JFiaE6l

[pinkflamingoes]

When we get to our bathroom setup we are going for composting toilet for sure. We bought a black tank but will probably sell it now. The only thing I can think of that Andy might be saying is not to discard a black tank because some next person who gets it may inadvertently use it for fresh water tank?

Look up some of those composting toilets! You can make one for $5 for disaster preparedness or buy a beautiful ceramic one for your rig. Lots of options. Great for cabins with no plumbing etc.

No black tank!! Woohoo!!

[Protagonist]

Originally Posted by cheetah1

Thank you to everyone for your responses! Has anyone ever replaced a tank in the back washroom (under the floor) and come up with a way to then access and be able to "service that tank" by dropping the belly pan in that area rather than having to pull the floor up if something goes wrong?

Don't think that's a good idea. The only way to service the tank from underneath is to put an inspection hatch in the belly pan, and a matching inspection hatch in the tank. But being on the bottom, as soon as you open the tank's inspection hatch, "Sploosh!" you dump the tank's contents out the inspection hatch— and in your face— rather than the drain valve where it's supposed to go.

You really need to access the tank from above for service unless the tank is bone dry.

Now, what you could do is put an inspection hatch in the floor alongside the toilet, so that you can access the top of the tank without removing floor or toilet, and a matching hatch in the top of the tank.

[Protagonist]

Originally Posted by pinkflamingoes

We bought a black tank but will probably sell it now. The only thing I can think of that Andy might be saying is not to discard a black tank because some next person who gets it may inadvertently use it for fresh water tank?

Easy solution. Get a Sharpie marker in a contrasting color, and clearly label the tank "Non-potable (non-drinkable) water only!" on both top and bottom surfaces. Then you can sell it, discard it, whatever, without worry about the next person misusing it.

[DGJackson]

Originally Posted by cheetah1

Does anyone have any suggestions for a source for the grey water tank at a reasonable price?

look at eBay for potential grey water tanks. there are lots of abs (black hard plastic) tanks there. I found one that I purchased for $125 and fit it under the floor in my 1973. The tank specs listed were: "RV Holding Tank, 32"X5"X57", Mid Side Drain, 39 Gal Black/Gray Water, New, #218"

I made seller an offer cheaper than posted and offer was accepted. This one worked for my application.

Note that this approach takes some skills since I had to build a mounting system and configure the plumbing to the tank. You just have to decide what level of skill you have, set a goal just past that, and go for it. There is lots of good advice (and some not so good) available.

Good Luck
Dennis

[DGJackson]

Originally Posted by DGJackson

Note that this approach takes some skills since I had to build a mounting system and configure the plumbing to the tank.

ps - this system is accessed entirely from the underside, I just made the belly pan in that part separate from the rest. a second piece of aluminum 4-ft wide coves this bay. I installed with rivet nuts, but that's probably overkill. I've also been told I have CDO, that's an extreme form of OCD - only alphabetical like any sane person would organize it. for normal people pop rivets would work. good luck - dennis