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Fresh water tank as grey water holding tank

PostPosted: Fri Sep 02, 2011 12:26 am
by atahoekid
I've been looking at grey water tanks and noticed they are WAY more expensive than drinking water tanks. Any particular reason why??? Could I use a drinking water tank as a grey water tank? It would just be to collect water from the galley sink. :thinking: :thinking: :thinking:

PostPosted: Fri Sep 02, 2011 1:12 am
by doug hodder
I'd imagine that since you aren't an "official" RV manufacturer you could do what you want on it. I'm sure there is some technical/governmental thing that makes that plastic specific for a gray water tank. Dish pans work great.

It's just my opinion, but I just can't imagine hauling gray water in a tear, but then I'm not that "green" of a person. At 8# a gallon...that could be a lot of unnecessary weight to haul around for dirty water. Gasp....I just dump it on the local bushes, and here in NorCal...All the tenters dump it, they aren't hauling it around. I think the bushes welcome it in mid summer. Any soap will break down clay/hard soils. I don't dump it with a lot of food stuff in it however. The Tahoe basin is a whole 'nother critter though. Doug

PostPosted: Fri Sep 02, 2011 4:39 am
by Shadow Catcher
Not something I know for sure concerning tanks but sewer pipe is tested per ASTM to handle soap which degrades certain plastics. My bet is you would die of old age before you have a problem.

PostPosted: Fri Sep 02, 2011 5:33 am
by glenpinpat
we use a fresh water tank to catch water from the sink. We have it marked with big black letters in permenant marker so we do not mix them up.

PostPosted: Fri Sep 02, 2011 6:14 am
by dh
Doug, my thoughts on grey water tanks in teardrops.

When in campgrounds where dumping grey water is prohibited, you are only traveling maybe 1/2mile max to the dump station with a full grey water tank.

When boon docking, the dump valve can be left open and a hose can carry it away from your campsight.

PostPosted: Fri Sep 02, 2011 6:47 am
by 48Rob
Water, soap, and other personal cleansing solutions aren't likely to cause a problem, but formaldehyde and other potent holding tank chemicals may.

I used a fresh tank as a gray tank for several years with no known ill effects.
(Sink water only, no chemicals except bleach, used to disinfect and keep odors at bay.)

Rob

PostPosted: Fri Sep 02, 2011 9:58 am
by Dale M.
I don't perceive it a problem, just plumb it is such a way that you don't accidentally connect a fresh water line to it and it may siphon back into water system and contaminate fresh water supply...

Dale

PostPosted: Fri Sep 02, 2011 9:05 pm
by dh
Wasn't there a post about a comertial camper company that did that? Plumbed the black tank to the fresh water system?

PostPosted: Fri Sep 02, 2011 9:07 pm
by dh
Oh, nobody's brough it up yet so I will, you'll want to vent it outside...

PostPosted: Fri Sep 02, 2011 10:55 pm
by atahoekid
dh wrote:Oh, nobody's brough it up yet so I will, you'll want to vent it outside...


I assume you're talking about the grey water tank being vented to the outside? The fresh water tank has a vent hose connected at the filler, Is that the right way to do it?

PostPosted: Sun Sep 04, 2011 2:30 pm
by dh
That is a good place to vent the fresh tank. Most RVs have the black/grey tanks vented like residential plumbing with a roof stack, not really apealing on a TD. Do not plumb grey water vent to the vent on the fresh water inlet. Also, I'd put an air admitance valve after the sink P trap so you don't siphon the waterout o the trap.

PostPosted: Sun Sep 04, 2011 3:18 pm
by Tabazooron
We just started with an empty kitty litter bucket. It has a handle for carrying. We eventually rigged up the top with a vent opening and a connection for the drain line.
Many campgrounds in Michigan do not want you to dump gray water on the ground, even though they never seem to say anything to tenters who dump their dishwater on the ground. Never understood the difference.
Ron Huster
T@Bazoo

PostPosted: Sun Sep 04, 2011 6:08 pm
by 48Rob
Tenters tend not to carry/use holding tank chemicals? ;)

Usually, blatant disregard will get you in trouble, while "easy does it" doesn't...

Rob