Fresh water AND grey water combined?

Dannyabear1 wrote:

...the grey and black tanks are not made for potable water.

Old-Biscuit wrote:

...The waste tanks are NOT made from material that is to be used for water that is consumed (potable)....

My Weekend Warrior has four tanks. Two tanks are fresh water, one for gray, and one for black. All four tanks are the identical black material.

I'm confused. Here is what I'm guessing at, and I have to split this between two scenarios:

1: The OP wants more fresh water, so wants all the wastewaster to dump to the black tank, and convert the gray water tank into another freshwater tank.

2: The OP wants to combine the grey and black tank.

I'd not even go near #1. Legal liabilities aside, it drastically kills the resale value of any trailer. Instead, I'd either buy bladders as described above or jugs of water (five gallon are decent, but some people may not be able to carry that much, so 1-2 gallon jugs may be an alternative.) Then, store those containers on a hitch mounted cargo rack, in the bathtub, or wherever. In a pinch, you can get RotoPax pack mounts, install those on the back or top, and use those for fresh water storage.

With my current setup, if I needed large amounts of additional fresh water, I'd buy a tank for the pickup truck, then use a 12 volt battery and pump so I can move water from the tank to the RV's fresh water inlet. If I needed 10-20 gallons, I'd just use five gallon jugs and pour them in by hand.


For option #2, this can be easily done. Buy a Valterra twist on valve, (CW#27868), install that, then pull the valves on both tanks. They will equalize. Then push the valves shut (so if the twist on valve gets bumped off, it doesn't mean a mess on the road.) I'd rather not have black water and its solids go in the gray tank, but if someone wants both tanks to act together, this is the way to do it.

Dewey is right -- if you find after a while that the tank is not big enough, you can always buy one of those bladders. You know what they say -- bladder late than never. ;)

There are far better solutions. Since the OP is talking about a brand new and never used Vehicle, then I assume he's not purchased it yet. Simply look for a trailer with a very large FW capacity. I have a 2011 bottom of the line Starcraft 235fb that has 90 gallon FW capacity. I bought it because I wanted the ability to have a lot of FW. There are many trailer models to choose from and some have very large FW tanks. If you want even more water, there are bladders for your tow vehicle, Gerry cans, 8 gallon portable containers, etc. Trying to modify a gray tank just doesn't seem smart. How will it impact the total weight of your TT? Usually they figure you start out with full FW tanks and as you use it, the black and gray tanks fill up. Traveling with full FW and GW tanks may leave you little spare weight for everything else (food, gear, etc) that you will want to take.

Old-Biscuit wrote:
... .
The waste tanks are NOT made from material that is to be used for water that is consumed (potable)...

And you think that because????

I have owned RV's with tanks (both fresh and waste) made from that translucent "extremely difficult to repair" polyethelyne plastic, and tanks made from easily repairable ABS which IS safe for potable water. Valterra sells "rocket tanks" athat are ABS and for potable water.

I think he is saying to use the Blk tank for grey and blk purposes. Then use the original fresh and grey water tanks both for fresh. No grey would have ever or would ever go into the grey tank. Seems the blk tank would fill fast...IMO

Question one might consider .. is the Grey tank constructed of material suitable for potable water as is the drinking water tank???

Perhaps we should have a new thread: Mods that I did that no one else should ever attempt.

ONE READON TO BE CAREFUL of buying a used RV. To many DIY out there.
Which would be OK if they tell the buyer what they did.

If you need more fresh water carry water cans that are made for drinking....wow
just add to fresh water tank if you need it in the system....use dish pan to wash and then use that to flush toilet