Adding additional water tank under the floor

[RowRV]

Hi

Does anyone know, or has anyone added an additional water tank and mounted it under the floor and to the frame? I have 9 people in our RV almost all the time when we travel and I need the extra water.

[aguablanco]

How much waste capacity do you have?
RichH

[ewarnerusa]

Originally Posted by aguablanco

How much waste capacity do you have?
RichH

^^^^ This. Without knowing how your group uses water I can't say for sure what will happen. For my family, we drink some and sweat/pee it back out outside and also lose some water to steam from boiling it. Also occasional outside sprayer usage. But then all the rest of the water in the fresh tank will eventually end up in the black and gray tanks. So you need enough capacity in the waste tanks to accommodate all of the fresh or else it starts backing up out of floor drains or toilets.

[Robert Cowan]

The additional weight would probably be a concern!

[Robert Cowan]

Originally Posted by RowRV

Hi

Does anyone know, or has anyone added an additional water tank and mounted it under the floor and to the frame? I have 9 people in our RV almost all the time when we travel and I need the extra water.

The addition weight would probably be a concern

[BertF]

Additional tanks are available in all shapes and sizes, but there are a few concerns. As already mentioned, weight is a very serious consideration, and you will need to find the space to mount the tank.
Check out all tanks available on this website: https://www.plastic-mart.com/category/33/rv-water-tanks

[OldOneTwo]

At 8.34lbs per gallon, fifty gallon tank would be 417 pounds in addition to your original tank weight. You might not have room to begin with.

[MartyG]

Assuming you're towing that with some kind of truck, I'd suggest you look for some potable water tanks you could keep in the truck. A 12V RV water pump and some hose would keep you from having to lug from one to the other; just connect the hose, and turn on the pump.

[Snowman53]

I concur with the weight issue raised. Water is heavy and adding an additional 300 - 400 lbs. to the bottom of a trailer could result in overloading, balance issues, and overall unhappiness. I get the capacity issue, as we typically camp in state parks or municipal campgrounds with no water hook ups. The back of the pickup idea has merit.

[franktafl]

this just came out today... maybe it will help a bit.

https://rvlife.com/grey-water-hacks/

[Captainkristopher]

Why not look into a water bladder? You can put it in your pickup bed or under your bed in the trailer when you need it. It’s not permanent so you can take it when needed. I wouldn’t worry about the weight of 400-500lbs. Two average people weigh that much now and we haven’t killed our trailers yet. Just my two cents.

[OldOneTwo]

Your two average people do not travel down the road in your trailer. At least I hope not.

[dsol]

I say learn how to take faster showers. That is the main culprit. Also, if you are boon-docking I would go longer between showers too.

Adding a tank will be a massive undertaking. Securing it, dealing with the added weight (both in increased weight on the trailer and potentially exceeding your trailer cargo limit plus balancing the load) and then pumping the water out will all be a challenge. You will also likely run out of gray tank capacity as well.

Personally, I would consider upgrading a trailer to a model with greater water and holding tank capacity before I took that on. My Voltage holds 100 gallons of fresh but only 80 gray and 40 black in the holding tanks so I could only add 20 gallons and that would require perfectly balanced use between kitchen and bath gray plus the toilet.

Anyway, good luck.

[dsol]

Just saw you have a 2021 4025 so I don’t think upgrading will be an option and you probably already have 150 gallons of fresh on board so you are in a tough spot here.

So unless you are towing with a 1 ton dually that extra weight—both fresh water and holding tank need will also likely bump up against your trucks max payload too.

Let us know what you decide.

[bkuuz1]

RowRV,

I know it's not exactly an answer to you your exact question, but I use one of these with a capacity of 60 gallons. It has severed me well over the last couple of years without an issues. I will put it in the back of my truck on a tarp to make sure it doesn't get a hole in it. For us, family of 6, it allows us to get some extra showers in when we are dry camping.


https://aquaflex.net/aquatank2.html

[Yosemite Sam]

Yeah, waste water tanks becoming full and overflowing will be a concern.

These waste water tanks are designed to take the current capacity of the fresh water tank.

And if you are making the trip dump a full grey water tank, you might as well refill your fresh water tank -- or vice versa.