How big should the tank be

[Desertsparky]

Im looking for tank size suggestions.

Family of 6. We are in the phx area so I tend to lean bigger when it comes to water haha.

Also grey and or black tank size. Im assuming we base that off the fresh tank but not sure how to size it.

I tried search toold but cant seem to find anything useful

[fo4imtippin]

How long do you want to off-grid? I'm going 150 gallon fresh, 60 gallon gray, and 30gallon black. The official answer is that grey and black added together should equal your fresh tank capacity or something, but I plan to drop when needed and have an outdoor shower. It's kind of up to you....

[flattracker]

One important consideration:
Water at room temperature weighs about 8.3 lbs. 100 gallons of water = 830 lbs. Water moves when driving. It will be the heaviest object in your bus. A family of six will likely use that 100 gallons in two days or less. If you stay in a place with potable water available and septic/sewer hookup, this isn't a problem.


Mount both of your water tanks (three if using grey water) securely.

[HamSkoolie]

There are TWO of us in a 40' rig and we're planning 200 fresh, 80+ black
40 or 50 gray, and 35 reclaimed.
Reclaimed (screen out big stuff, 2 or 3 paper filters, RO filter, UV sterilzation) will feed shower, washing machine, and toilet flushing.


We don't think we have enough.

[turf]

i have a 48 gallon fresh tank and, 48 gallon black tank.

i bought 2 of the 48 gallon tanks for fresh water, but frankly, the 2nd tank takes up too much room.

48g/48g last me solo - 2weeks, with a partner, 1 week.

[Desertsparky]

Originally Posted by fo4imtippin

How long do you want to off-grid? I'm going 150 gallon fresh, 60 gallon gray, and 30gallon black. The official answer is that grey and black added together should equal your fresh tank capacity or something, but I plan to drop when needed and have an outdoor shower. It's kind of up to you....

Thats kind of what I figured. This will mostly be a camping rig with one longer cross country trip a year. Again being in a desert id love 200 fresh but that also feels overkill haha.

[Desertsparky]

Originally Posted by flattracker

One important consideration:
Water at room temperature weighs about 8.3 lbs. 100 gallons of water = 830 lbs. Water moves when driving. It will be the heaviest object in your bus. A family of six will likely use that 100 gallons in two days or less. If you stay in a place with potable water available and septic/sewer hookup, this isn't a problem.


Mount both of your water tanks (three if using grey water) securely.

That seems like a ton of water use per person. Especially for a non flush toilet. However I do get the point. I see a lot of videos with all thread and unistrut that are intriguing but I feel like they need more support.

[Desertsparky]

Originally Posted by HamSkoolie

There are TWO of us in a 40' rig and we're planning 200 fresh, 80+ black
40 or 50 gray, and 35 reclaimed.
Reclaimed (screen out big stuff, 2 or 3 paper filters, RO filter, UV sterilzation) will feed shower, washing machine, and toilet flushing.


We don't think we have enough.

Id love to see that setup. As Ive said we are in a desert and our water sources are drying up but it is probably over complicated for our needs yet.

[Jolly Roger bus 223]

what fixtures do you plan on using?
you can put water savers in all fixtures.
a toilet at 1.3gpm
a kitchen and or bath faucet at 1.0
a shower can go lower but wont rinse the shampoo out of a ladies hair very good or efficiently.
for shower a hand sprayer where you get wet lather up and rinse of is probably the way to go to save water.
for capacities you need to add all of that up and see where you are at with the time durations of filling the sink to wash dishes and rinse dishes and each person doing there thing in the morning.
i grew up camping out of a back pack so my familys routine on a trip is different than most.
a bus is our only upgrade and more of a mobile base to make longer excursions shorter.
outdoor showers still draw fresh but nothing in the gray.
if filtered you might want to fill your canteens for a hike.
for my big bus i have 200 fresh a 80 gallon grey and a 100 gallon black but that was from a winnebago setup.
my idea with a black tank is the solids are going to take up some of that room but you need the liquid in there to move the solids upon drainage.
for grey tank you dont get as much solids but hair or food from not scraping plates or paper plates for the fire pit.
with an outdoor shower i would want the extra capacity but with out one i would think the fresh tank should be less that the total of both tanks and calculated solid accumulation for your build i would want a little left but not overflow the tanks from being over full .
but they do make tank monitoring systems as long as the tanks are built with the connections for them.
and i might be to old school where they have a wireless one now

[HamSkoolie]

Originally Posted by Desertsparky

Id love to see that setup. As Ive said we are in a desert and our water sources are drying up but it is probably over complicated for our needs yet.

Guessing you mean the reclamation set up. It's planned out and simple. Not sure how well it will work but we will at least be able to reduce some water usage be reclaiming. Basically, everything goes to the black tank except the Shower and Washing machine. So toilet, bathroom sink, and kitchen sink. This keeps out food particles, tooth paste, etc.


Washing machine and shower go into the gray tank from which a pump pulls water through a screen to remove hair, lint, etc. (washer will have lint screens to minimize lint in the tank). Then it will go through two or three filter elements to remove smaller particles, and then through an RO system.
RO systems typically send 19 parts of water down the drain for every part processed through the membrane so the RO "waste" will be fed back to the gray tank.
After RO processing, the flow goes through a UV sterilizer and into the reclaimed water tank to be drawn upon for toilet flushing, showers, and washing machine.
Because there is then a reclaimed and a potable system, we will need three water pumps (fresh, potable, and the reclamation filtering system), and two on demand water heaters (potable and reclaimed systems).
A bit of extra expense but we would like to take nice, long, HOT showers rather than the typical wet, lather, rinse deal.

[Rucker]

I have a composting toilet and the system is designed for two people, four days off grid. 40 gallons fresh water, 40 gallons gray.

That's based on a bunch of Internet research, so until I take the rig out I can't say it's more than a good guess as of right now.

[Veloc]

For my eventual build, the waste tanks will have a larger capacity than the fresh tank, probably by 20 percent. So, if I had 100 gallon fresh, I'd go 120 gallon grey/black with any overflow to the grey tank heading for the black tank. The reason? I don't want to risk anything, including a fresh water pump getting stuck on and pumping its entire contents to grey/black, to result in anything backing up into the living quarters. I also don't really plan to boondock more than a few days at a time while traveling between destinations. Worse comes to worse I can always pull into a national park for a water swap.

[N5tavniec]

I am planning on 200 gallons fresh, 100 grey, composting toilet. A bit extra for 1-3 people. But I'd like the option to boondock for awhile. I figure some of the water will be used outside for cooking, rinsing/washing, filling up water bottles and the like.

[flattracker]

Just remember each gallon of water weighs 8.33 lbs and the weight of the tank and mounts. 200 gallons of water weighs 1,666 lbs plus 100 - 200 lbs for the tank, and mounts. If you mount below floor be concerned about outside air temps.

[Danjo]

It’s all about learning to live without water. You can’t of course, but if you intend to live untethered you need to figure out ways to not use it or use less of it. Like using paper plates, making one pot meals, bucket baths, and so on. Even then, if you’re out of campgrounds for any amount of time your life will include the search for water spigots and dump stations

[Clouse House]

Originally Posted by N5tavniec

I am planning on 200 gallons fresh, 100 grey, composting toilet. A bit extra for 1-3 people. But I'd like the option to boondock for awhile. I figure some of the water will be used outside for cooking, rinsing/washing, filling up water bottles and the like.

Originally Posted by flattracker

Just remember each gallon of water weighs 8.33 lbs and the weight of the tank and mounts. 200 gallons of water weighs 1,666 lbs plus 100 - 200 lbs for the tank, and mounts. If you mount below floor be concerned about outside air temps.

I have two 120 gallon tanks for fresh and two 120 gallon tanks for grey. Making 240 gallons of each.
With two little boys that like to roll in dirt and a wife that loves her plants, I figure we'll go through a lot of water.

As flattracker said though, be mindful of how much the water will weigh and how weather will affect it.

I'm mounting my tanks using a cage made of 3in angle iron with plenty of 1in flat bar supports in order to handle the weight in the unfortunate event of an accident. I'm also looking into getting some baffle balls to help with liquid surge. The location of large tanks is also important for weight distribution. My fresh tanks are going between the frame rails (why I wanted a RE bus) evenly distributed between the front and rear axles. My grey tanks are going outside of the frame, one on either side, positioned 2/3 of the way toward the rear, as the rear axle can support more weight. This means that after a flush and fill the weight is evenly distributed but anytime after the water is used that weight starts shifting to the rear. The grey tanks are also going to be connected to each other via a 6in ABs pipe in order to balance weight between the driver and passenger side. The drain will be coming off of this 6in pipe in order to prevent it from clogging.

As far as weather is concerned, they sell 50 gallon tank heating pads for a decent price and I plan to have two under each tank. It'll be slightly undersized at 100 gallons of heating for a 120 gallon tank, but I'm hoping that adding 1/2 of insulation on all sides will help with that. Plus I'm adding a hot water circulation route that dumps clean hot water back into the fresh water tank, the idea was so that no water is ever wasted while waiting for hot water at the tap, but it'll also help incase I ever need to thaw out the fresh water tank.

I already have the tanks and the metal, after I finish resealing the windows, it's my next step. I'm excited and scared I'll mess it up.

[Rucker]

Originally Posted by Danjo

It’s all about learning to live without water. You can’t of course, but if you intend to live untethered you need to figure out ways to not use it or use less of it. Like using paper plates, making one pot meals, bucket baths, and so on. Even then, if you’re out of campgrounds for any amount of time your life will include the search for water spigots and dump stations

Good point. Skoolies (and boondocking) require a change of approach to things like electricity and water consumption. And I've found by designing the bus to live with less gives me a greater appreciation for how flagrant my electric and water usage is at home.

I mentioned above that I have 40/40, and that's worked out perfect for 2 people, 4 days in California state park campgrounds. In reality I have 25 Freshwater, three 6 gallon jerrycans, and 40 graywater. We're careful with water but probably don't need to be.

When we used to go camping with the 5 kids we just let them jump in the lake to stay clean. After the second day everything was covered in a fine layer of dust, and I'm not sure how often I actually changed.

I can see how it would be different if you lived full time in a bus, unless you want to be that family.

[Ronnie]

We have 105 gallons fresh, and can go a week (for two people) with modest showers or two weeks with navy showers. Rv toilet, no human litter box.


60 gallon grey.


50 gallon black.

[HamSkoolie]

Originally Posted by Danjo

It’s all about learning to live without water. You can’t of course, but if you intend to live untethered you need to figure out ways to not use it or use less of it. Like using paper plates, making one pot meals, bucket baths, and so on. Even then, if you’re out of campgrounds for any amount of time your life will include the search for water spigots and dump stations

Or use reclamation techniques.
For those who have flush toilets (some of us don't buy the "convienience" of "composting" toilets) a fairly simple filtration system can use gray water to supply flush water.
A more complex system (pre filters, reverse osmosis, UV sterilization) can reclaim shower and washing machine water for reuse in those two applications. This would allow all but unlimited showers and washing machine use (dependent upon the filtration system capacity).