Grey Tank, What the point?

[hotdog]

Hi,

We are relatively new to Fun Finders with a about 3000 miles in the last six months, we mostly "dry" camp.

We have a 2011 X160 with 25 gal fresh tank, 32 gal grey tank, and 25 gal black tank.

The waste water tanks have separate drain valves and I have figured out that the shower and toilet are plumbed to the black tank and only the sink is plumbed to the grey tank. We never come close to filling the grey tank.
Personally, I would prefer that the shower be plumbed the grey tank as well.
Is this a typical set up?

[APD]

The only thing going into our black tank is the toilet. Shower and sink to the gray.
I'm fairly new to FF as well but I believe that's more typical in camper design.
Our rig is older and a different model. Maybe a X160 owner will chime in.


Alan

[Eagle]

In my XT 276, only the toilet goes into the black water tank. Sinks and shower waste water go into the grey water tank. No idea why the X160 would be plumbed different?

[John_C]

Originally Posted by hotdog

Hi,

We are relatively new to Fun Finders with a about 3000 miles in the last six months, we mostly "dry" camp.

We have a 2011 X160 with 25 gal fresh tank, 32 gal grey tank, and 25 gal black tank.

The waste water tanks have separate drain valves and I have figured out that the shower and toilet are plumbed to the black tank and only the sink is plumbed to the grey tank. We never come close to filling the grey tank.
Personally, I would prefer that the shower be plumbed the grey tank as well.
Is this a typical set up?

Hi Hotdog,
Some of the older RVs were and some cases, some are still being built with a combination black and grey water tank. This makes the plumbing costs of manufacturers go down. However, the combined tank would need to be much larger or would require more frequent draining than a typical 3-Tank system. Therefore, separate grey and black water tanks are most common.

By definition, grey water, does not include the discharge of toilets or fecally contaminated wastewater. Grey water is all the water used in your RV, except what goes to flush the toilet... Toilet water is called black water.

The water used for everything else, showering, cooking, washing dishes and all other water-related activities goes into the grey water tank.

Both grey and black water tanks have separate drain valves, but typically drain into a common "dump" valve and outlet.

If your shower should drain into the black tank and not into the grey tank, you will fill the black tank much quicker than normal; thus, the reason the grey tank being larger than the black tank.

I found a brochure for the FF X-160 and it posted tank sizes as:
Fresh Water Tank (gal.) 25
Gray Water Tank (gal.) 32
Black Water Tank (gal.) 25

I have an '08 XT-190 and have separate tanks as follows:
Fresh Water Tank (gal.) 35
Gray Water Tank (gal.) 40
Black Water Tank (gal.) 25

The black tank is generally smaller due to less waste and the grey water is typically larger and often larger than the fresh water to prevent excessive waste water overflow.

A very long response, but you might check to see if you have all three tanks and if so, the shower should NOT run to the black tank.

You should also have a drain on each of the Black and Grey Tanks, in the normally closed position and if plumbed as my trailer, these should be connected to a common drain (where you connect the drain hose).

Upon draining, you would drain your black tank 1st and flush it to clean any residual matter, then close the black tank valve, while leaving the common drain valve open... Now open the grey water tank valve. The grey water will help flush black tank water from your hose and common drain valve. Flush the grey tank to clean drain and then, close the grey water tank valve and then close the common drain valve. At this point I disconnect the drain hose from the common drain and flush it with fresh water, drain completely, then remove from sewer dump and stow. I also spray the dump valve and reinstall the cap (I use a clear cap to check for leaks)...

P.S. When finished as above, be sure to add water (several gallons, as water is your best friend here, and whatever tank cleaner/digester/valve lubricant to your black and grey tanks)...
Good luck, and as always...

[hotdog]

Thank you for the reply. Your dump process makes a lot of sense. Unfortunately I do not have one common dump valve. I do have three tanks as stated and two separate dump valves. So one has to switch the hose to dump both tanks.
The shower which is directly over the black water tank is definitely plumbed to the black tank so it tends to fill up fast. The grey tank which only is used for the sink never fills up.

Given the layout of my x160 (with the sink on the other side of the trailer), I think it was easier (and cheaper) to plumb the shower to the black tank. The only positive I can see in this setup is there is more (fresh) water is the black tank.

[LJAZ]

Some manufacturers do that with models that have the shower directly over or close to directly over the black tank. I think simply because it's easier and cheaper to do it that way. but to not have the drains dump through a common outlet is pretty unusual. Typically as John C said you 'rinse' the lines after draining the black tank with grey tank. Plus then you don't have to monkey around moving the fitting. Did it come that way new?

[APD]

Originally Posted by LJAZ

Did it come that way new?

That's my question too!
Seems like that set-up would seriously limit your shower time!!!

[Eagle]

And increase your waste water dump events! ;-O

[John_C]

Hi Hotdog,
I am sorry your trailer is plumbed with the shower to the black tank, this does limit showers when dry camping. Out of curiosity, what size tanks do you have; are they sized as in my earlier post??

As far as there being two dump valves in lieu of one, there are both configurations in trailers and I am sure that a bit of plumbing mods, one should be able to combine them into a single valve...

Good luck...

[profdant139]

So let's look on the bright side here -- this setup means that you will have an unusually clean black tank -- rinsed frequently with soapy water! When boondocking, we sometimes take our soapy gray water in a bucket and dump it into the black tank. (We do that because the gray tank fills faster than the black tank, but it does help dilute the contents of the black tank.)

[hotdog]

Yes I have a nice clean black tank, all the level indicators work. Here is a pic of the dump valve set up.
We have a 2011 X160 with:
25 gal fresh tank
32 gal grey tank
25 gal black tank

.....Someday, I will plumb the shower to the grey tank.

[John_C]

Originally Posted by hotdog

Yes I have a nice clean black tank, all the level indicators work. Here is a pic of the dump valve set up.
We have a 2011 X160 with:
25 gal fresh tank
32 gal grey tank
25 gal black tank

.....Someday, I will plumb the shower to the grey tank.

It's a shame that a cheap install forces the owner to replumb the sewer system on a trailer... The only thing the manufacturer saved was a few feet of ABS pipe and very little labor...
In looking at your pic, when you replumb, add a Street-L (a sweep-L) from the discharge side of the grey tank valve to a another Street-L into a 3" Tee at the discharge side of the black tank valve, dumping to a 3" bayonet common drain...

You shouldn't have to do this as the manufacturer should have done it right...

BTW, I have an old Shorewood RV Center (Anoka, MN) catalog and it had a ton of stuff for RV sewage lines, connections, valves, and fittings... Maybe they can send you a catalog; that will give you something to help make decisions, whether you buy there or not... Good luck...
Shorewood RV | Minnesota RV Dealer, Sales, Service, Parts, RV Rental, RV Restoration

[Michigantraveler]

Never heard of such a setup. We never use the shower in ours...too small. But it is really important to use the gray water flush after emptying the black tank. I save the dishwashing water with Dawn in it and we use it to flush the toilet. Dawn is a great product. It really does dissolve grease. Periodically Using some liquid Calgon with Dawn for a thorough cleaning can clean out the black tank as well. It makes the tank sides slippery.

[lucynricky]

I’m onto this thread late, but am going to post this anyway for the benefit of any new readers.

This is a quick and inexpensive fix to increase holding capacity and fix valve leak issues.

In the case of the OP, simply plumb your two valves into one outlet and attach this $23.00 Valterra “twist on valve” (Camping World usually has in stock). Those with one sewer drain outlet, this takes about three seconds to install.

It increases capacity by allowing you to open both gray and black tank valves and letting the water levels equalize, giving you one large waste tank. And it provides an added valve in case one of the others should leak or fail.[IMG][/IMG]