Adding a “supplemental” gray tank?

[bigorange]

We love the floorplan of our new 5er, but I’m not happy with the holding tank capacity...primarily gray. I’ve thought about replacing the tank with a larger tank, but I’m wondering if it’s possible to plumb another tank onto the existing tank with a high and low connection to equalize between the two and effectively double the capacity,.or would I be better off adding a second tank and plumbing it separately to the galley sink and leave the shower/bathroom sink to the old tank?

Yeah...next trailer we buy the tank capacity will be a top consideration. Floorplan won out on this one at a cost...

[Lantley]

I like the tote idea because it is easy to do however. The tote creates additional work. If you can gain enough capacity by equalizing grey tanks or grey and black tanks that would be my first choice.
Equalizing may involve some creative piping. Next option would be adding a 2nd tank which simply may not be feasible.
The tote becomes the 3rd option. It will add capacity and is easy enough to do.
I would get a 42 gallon tote for maximum capacity if I went this route.

[dodge_guy]

I would go with a 20 gallon tote. this way you have extra capacity and you can drain your tank without moving the RV.

[ericosmith]

Old-Biscuit wrote:

ericosmith wrote:

Halmfamily wrote:
If you have both grey and galley tanks add an external gate valve. Keep the external gate valve closed and open both the grey and galley they will equalize each other. I now have 120 gallons of grey capacity by doing this.

I did this a long time ago but nothing happens. I can't for the life of me figure out why they don't equalize.

Where are your tanks located?
DO they use the same drain line to sewer hose?

Extra valve on common drain closed and black/grey tank drain valves open ----water seeks it's own level (higher level flows to lower level until same level)

I'm not sure where the tanks are located but they share a common drain line to the external gate valve. The bathroom fills and the kitchen stays almost empty. The bathroom is on the upper level as opposed to the kitchen with is on the lower so it's counter intuitive to think the bathroom is lower than the kitchen. When I open the individual drains with the gate closed, the sensors don't move a bit either way.

[2gypsies1]

Check carefully. Most RVs are built around the holding tanks with no room to spare.

[Old-Biscuit]

ericosmith wrote:

Halmfamily wrote:
If you have both grey and galley tanks add an external gate valve. Keep the external gate valve closed and open both the grey and galley they will equalize each other. I now have 120 gallons of grey capacity by doing this.

I did this a long time ago but nothing happens. I can't for the life of me figure out why they don't equalize.

Where are your tanks located?
DO they use the same drain line to sewer hose?

Extra valve on common drain closed and black/grey tank drain valves open ----water seeks it's own level (higher level flows to lower level until same level)

[ericosmith]

Halmfamily wrote:
If you have both grey and galley tanks add an external gate valve. Keep the external gate valve closed and open both the grey and galley they will equalize each other. I now have 120 gallons of grey capacity by doing this.

I did this a long time ago but nothing happens. I can't for the life of me figure out why they don't equalize.

[dave17352]

Old-Biscuit wrote:
All of your tanks are small.........that is typically due to lack of larger spaces to install tanks

50 gal/fresh
28 gal/grey
28 gal/black

Install an addition 3" dump valve on common drain header.
Close it...open black/grey and combine them for 56 gal waste tank capacity

Grey is just as nasty if not worst then black....body oils/sloughed skin cells, grease/oils, food debris, urine etc

RVs use to just come with ONE waste tank.

I have 3 waste tanks on my 5vr...added the extra common valve when first bought it back in 2006 (128 gal waste capacity)
Previous 5vr added the extra dump valve

Simple easy means of increasing waste capacity

Or buy the twist on version that goes on end of drain pipe.

x2 the nice thing about this is now you know you can fill the water tank and know you will not overfill the grey or black tank.

[Old-Biscuit]

All of your tanks are small.........that is typically due to lack of larger spaces to install tanks

50 gal/fresh
28 gal/grey
28 gal/black

Install an addition 3" dump valve on common drain header.
Close it...open black/grey and combine them for 56 gal waste tank capacity

Grey is just as nasty if not worst then black....body oils/sloughed skin cells, grease/oils, food debris, urine etc

RVs use to just come with ONE waste tank.

I have 3 waste tanks on my 5vr...added the extra common valve when first bought it back in 2006 (128 gal waste capacity)
Previous 5vr added the extra dump valve

Simple easy means of increasing waste capacity

Or buy the twist on version that goes on end of drain pipe.

[down_home]

Might be easier to just replace the tank with a larger one, if you can locate one.
The store in Elkhart that had all kinds of different parts and replacement parts was bought by Camping World and no longer sells to anyone.
I have no idea hat is happening with the inventory since no one is buying there replacement or other parts from Camping World. Camping World is all about selling new units. Repair parts etc are from the factories and may take weeks or even months. Maybe someone here, knows the situation today.
I would like a larger fresh water tank and gray would be good too. Black is plenty big.

[Halmfamily]

If you have both grey and galley tanks add an external gate valve. Keep the external gate valve closed and open both the grey and galley they will equalize each other. I now have 120 gallons of grey capacity by doing this.

[Pirate1]

I added a second gray tank to my motorhome. It's 35gal. It is situated between the stock gray tank and valve so I can use gravity to fill it and empty. I doubled my capacity. I only use it when primary tank is full. Pull the valve, it all fills up secondary tank, close valve, primary tank ready to use again. Vent on secondary tank is a 1/2" 90deg fitting which the tank came with.

[dave17352]

How about equalizing your black and gray tanks. I do this on my truck camper with zero issues. Its all sewage.

[pfidahospud]

Not necessarily advocating this, but depending on where and how you camp, sometimes the local trees and shrubs need watered. Just sayin’.