Teardrops n Tiny Travel Trailers

Hello everyone. Lots of great info here.

I am installing a shower in the v nose section of my 7x16.
I intended to put a grey water tank directly under the shower,
but the center of the tongue comes back too far. I can't move
the shower back any due to space limitations for cargo, so what
are my options? It seems all the waste tanks have the inlet on
the top. Can I get one with the inlet on the side toward the top
and run a hose from the shower drain to the tank? Will I have
issues with the inlet being barely lower than the shower drain?
What about a vent?

Sorry for the barrage of questions!
Any help will be greatly appreciated!

You don't have to put the shower above the tank.. Infact you can run the drain several feet to the tank.. My shower is about 5' away from my tank. You just have to put a slight fall on the line. You also need a trap on the line so having the shower right above the tank causes some issues with getting a trap under there. You can get an undrilled tan and put your own inlets in. With a ABS tank you just glue the fittings on.. With a poly tank you use a rubber grommet. Drill a hole stick the grommet in and the pipe runs through it.

Sorry forgot about the vent question.. Yes you need a vent. With the grey water tank you can also put that in the upper side of the tank. The top is better though. My vent is on the side in my grey water tank and on the top of my black water tank. If you do them both in the side I would put the drain from the shower just a little lower then the vent.. The pea trap will stop any gasses from coming up through the shower anyway.

I have been thinking about putting in a rv toilet and a black tank the problem is the space in the vnose where I want to put the toilet under that there is no room for the tank.
I have room for the tank further back but I would have to raise the toilet and elbow down from the toilet over and then down into the tank.
I am not sure if it's worth the effort,I am just a little tired of useing and dumping the portable toilet.
anyone have any photos or guide to installing the toilet and tank and what type fittings are used on the tank to empty it?

I put a full bath in my last two cargo trailers. Both were a little different. Its really not all that much to it if your already putting in a water tank a pump and grey water tank.. Adding a black water tank and toilet isn't any more trouble.

I have a few pictures in my toy hauler thread.. Really though its kinda of hard to take pictures of the plumbing. To bad I can't draw to save my life cause a diagram would be better.

Basically you have freshwater tank with a 1 1/4" Inlet for filling a 3/8 vent line. Then a 1/2" line for your supply to the trailer. That supply line connects to a 12v on demand pump. From there your pump feeds your fixtures in the trailer. Between the output of the pump and the fixtures in the trailer you connect your city hook up. This is where you screw a hose pipe in if your some where you have water. The pump keeps the city water from filling the freshwater tank.

Grey water tank needs a vent through the top or side up to the roof. 1 1/2 is pretty standard. Most tanks have a 3" outlet. For grey water tank you can use a bushing to reduce this to 1 1/2" for the drain.

Black water needs a vent in the top through the roof. Vent should be 1 1/2" or 2". Tank has a 3" drain.. You do not reduce this one. Any RV store will sell Dump valves. They offer a few different styles or shapes. Its pretty much two gate valves connected together in a T shape.. You have a 1 1/2" or 2" on one side for the grey water tank then a 3" gate valve on the other side for black water tank.. The gate valves can be easily removed with 4 bolts if you need to replace one. Below is what the dump valve looks like.

Both tanks will drain out of that single outlet.. When you dump your tanks, you drain the black water tank first, close the valve then dump the greywater tank. The idea is not to get black water in the grey water tank/plumbing thats why you close that side off. Doing the greywater tank last also rinses out your hose and valve. Hope all that makes since!
Here is what the valve looks like on my trailer..

Thanks for the replies.

Can I use the same kind of tank that I have
for freshwater for grey water? I can get them
a lot cheaper than the waste tanks I've been
finding. I'm not planning on a black water tank
at this time.

I have the water sink and shower installed and I always boondock in woods and fields so I am letting that water run out on the ground.


this photo is the space I am useing and I have moved the water tank so I have that space also,but under this area there is not enough room for a tank.


I am just looking at a way to install the toilet and black tank > I guess I will have to wing it as I go.
but it looks like I will have to build wood box 8-10 inches tall that the toilet will go on top so I can install a elbow that would go towards the back of the trailer past the frame and then drill down and install the tank where it will fit under the trailer.?

Xtremespeed wrote:Thanks for the replies.

Can I use the same kind of tank that I have
for freshwater for grey water? I can get them
a lot cheaper than the waste tanks I've been
finding. I'm not planning on a black water tank
at this time.

You might could. Depends on the tank.. I paid 50.00 bucks each for my tanks on ebay. They are 36 gallon poly tanks. ABS tanks tend to cost a little more then poly tank. The reason you need a waste tank is cause they are sloped and already have a 3" drain at the end.

jwhite wrote:I have the water sink and shower installed and I always boondock in woods and fields so I am letting that water run out on the ground.


this photo is the space I am useing and I have moved the water tank so I have that space also,but under this area there is not enough room for a tank.


I am just looking at a way to install the toilet and black tank > I guess I will have to wing it as I go.
but it looks like I will have to build wood box 8-10 inches tall that the toilet will go on top so I can install a elbow that would go towards the back of the trailer past the frame and then drill down and install the tank where it will fit under the trailer.?

With a black water tank and toilet you need the toilet directly above the tank. There isn't enough water in a flush to move waste down a line very well. That toilet area is pretty small and with the framing under the V it would be pretty tough. You might could find a tank small enough to set on the floor and build a platfrom above it for the toilet. Then just have the drain run out the bottem or even the wall of the trailer.. I don't think you will be able to put the tank under the floor though inless you move the toilet back out of the V..

BTW the other option you could do is mount an RV toilet with a Water supply there and just have a pipe drop straight down below the frame a little.. Then just slide one of those porable blue tanks under there when your at the camp site. This of course would only work if you were staying at a camp ground with a dump somewhere so you could dump the portable tank before you left.. Having everything on board would be a Much better and easier option though.

You know I didn't think about putting the tank in the trailer with the toilet on top but that would work and would be eaiser than below the trailer.
I travel by myself and normally camp about 3-4 days and the portable toilet has worked fine and it only holds 5gallons.
All I am wanting to do is eliminate haveing to use and dump the portable toilet I just want to get home and open the tank and dump it and run fresh water through it.
I would guess that a tank like my water tank could be modified easily?
I have a 16 gallon water tank and I use about a gallon a day = so a tank that size should work fine.?
I am sure after I get the toilet and tank it shouldn't be to hard to do.
I guess the only tricky part would be cutting the holes in the top and bottom of the tank everything else should all fit together and could be bought at lowes>?

Do I really need a 3" drain for just a grey water tank?
I've never stayed at an rv park so I'm not real familiar
with the hookups and dump stations. I just assumed I
could use a small 1/2" drain. I have 42 gallons of
freshwater so I need a comparable grey water tank that
is narrow enough to fit between my 24" frame rails.
They seem to be between $200 and $300. I only paid
$120 for my 2-21 gallon freshwater tanks.

Xtremespeed wrote:Do I really need a 3" drain for just a grey water tank?
I've never stayed at an rv park so I'm not real familiar
with the hookups and dump stations. I just assumed I
could use a small 1/2" drain. I have 42 gallons of
freshwater so I need a comparable grey water tank that
is narrow enough to fit between my 24" frame rails.
They seem to be between $200 and $300. I only paid
$120 for my 2-21 gallon freshwater tanks.

You don't really need a 3" drain for grey water. Like I said above you can reduce it as small as 1 1/2", But the dump valve has a 3" output. This is because a standard RV sewer hose is 3". The dump station at a Camp site will also be either 3" or 4". I mean if you have a smaller tank and good screens on all your drains you could just use a hose pipe to drain the water.

I just hate to pay that much for a grey water tank, but if I use the same kind of tank I have for freshwater, it's only going to have a 1/2" drain. I guess I'll just have to pony up the $.

Xtremespeed wrote:I just hate to pay that much for a grey water tank, but if I use the same kind of tank I have for freshwater, it's only going to have a 1/2" drain. I guess I'll just have to pony up the $.

Really do some searching and don't get in a hurry.. Like I said I paid 50 bucks each for my 36 gallon tanks. Thats really very cheap for what they are.. I just looked on ebay and the company I got mine from has 27 gallon tanks posted for the same price. Just search on ebay for RV holding tank. Shipping was around 25 bucks I think. If you can find a RV holding tank with for less then a 100 bucks your getting a pretty good deal..

The problem is, it has to be less than 24" wide to fit between the floor joists and less than 8" high for ground clearance. My size requirements is where the cost go's up. I've been watching ebay for a while. I have found a few around $130 but almost $60 shipping.

I definitely appreciate all the help!

There is a 22" wide for $125/make offer right now on ebay. Make an offer, ya never know. If you have access to a rv used parts supply house or watch wrecking yard. I see wrecked trailers off and on at various wrecker locations. Parts off of these are generally pretty cheap.