Fresh Water Supply Considerations

Tango-SKO

Senior Member
Joined
Mar 26, 2011
Posts
8,462
Location
Houston, Texas
Howdy All --- I just wanted to share some thoughts and open a discussion on this topic.

I've owned or leased any number of RV's over the years, most of which came with the fresh water system already on board. For my '46 Shorty, I am building it from scratch and hope to apply what I've learned and whatever you folks might want to contribute. My biggest peeves with all the built in systems was that the typical polyethylene (white translucent plastic) tanks...A.) make the water taste funky and "plasitcy"...and B.)...are prone to mold & algae growth...and C.) rarely if ever have any baffling.

This time, I plan on using interior mounted ABS (a black plastic) tanks as they impart no unwanted flavor to the water, are baffled and are algae & mold resistant. The only ones that seem to be on the market unless you spend big bucks to have one custom made are from Valterra and are limited to certain dimensions. They are all 8" x 16" x whatever length which can make for limited applications. In my case, I will be using three 12 gallon tanks conjoined to yield a 36 gallon system. Plenty for my solo use.

ABS Water Tanks Archives - Valterra.com | Valterra.com

The ABS is also much easier to work with in that you can use ABS cement to install hose connections and such where the polyethylene can only be "spin welded" and the joints are commonly prone to leaking if not professionally installed.

I have my "City Water" and "Gravity Fill" inlets which will both have inline filters and will back them up with another pre-pump filter. There are a host of other fancier filters, but I believe I can get by with these since the majority of my drinking water will very likely be bottled and hope to only occasionally rely on local city water for that purpose since it varies so greatly around the country in terms of quality.

Mind you, this will be a very simple system consisting of a single kitchen sink, a hand-held shower and one outdoor connection (very handy for cleaning off muddy boots or whatever else you don't want to drag inside). The internal & any external plumbing will all be PEX lines which also does not impart taste and has a good measure of freeze resistance. I am still shopping water heaters but leaning towards a tankless unit since they conserve a great deal of propane. I am even thinking about having a second, electric water heater for the occasions when I might have the necessary 110v hook up such as you find at RV parks and some campgrounds. That would free up extra propane for cooking (I still prefer fire for that..it's a primal thing).

I welcome any ideas, thoughts or plans you all might have regarding this very basic need.
 
You are going with just a 36 gallon tank? I too will be on board most of the time alone and do not see me being away from civilization more than 2 or 3 days at a time. From everything I have read I was feeling like I had to have a 100 gallon tank?!? Cost of shipping is at least as much as the cost of the tank!!
 
As I understood it, the trouble with algae growth in white polyethylene tanks arises only because they're translucent and light can pass through which supports photosynthesis inside the tank. The algae don't feed on the plastic itself. If one were to install a poly tank in such a way that it's shielded from all light, perhaps by insulating the tank with something opaque, I believe I've read it would be equal to the ABS in terms of algae avoidance.

I don't know about the taste effects of poly tanks. Remember that PEX is polyethylene too (albeit cross-linked) and many bottled drinks are packed in HDPE or LDPE bottles, too. Maybe the taste problem arises from inadequate sterilization of the water system? Even if it's filled with chlorinated city water, the chlorine will off-gas fairly soon so un-tasty things might be better able to grow in the tank and plumbing?

The point about DIY solvent welding ABS vs spin-welding (heat fusion) of the poly is a good one.

I'm thinking of having only a pressurized city water inlet (no gravity fill). It would go through a filter and then to the facilities. A valve bypass around the water pump would allow city water to fill the tank. The tank needs a vent anyway for pumping the water out, but probably the vent will have to be enlarged a little to avoid pressurizing it while filling. I'll know the tank is full when water starts flowing out the vent.
 
While I much prefer a City Water (pressurized hose) connection where available, I cannot count the number of places I have stayed where the hose end was so battered it would not attach and/or leaked a substantial sized pond next to my rig in very short order. The gravity fill at least provides a back-up plan for getting fresh water into the system.
 
Right you are! I forgot to mention I'm hoping the Camco "Water Bandit" product will be as good as advertised for that sort of situation. I have one already, but haven't had to test it yet.
 
Howdy All --- I just wanted to share some thoughts and open a discussion on this topic.

I've owned or leased any number of RV's over the years, most of which came with the fresh water system already on board. For my '46 Shorty, I am building it from scratch and hope to apply what I've learned and whatever you folks might want to contribute. My biggest peeves with all the built in systems was that the typical polyethylene (white translucent plastic) tanks...A.) make the water taste funky and "plasitcy"...and B.)...are prone to mold & algae growth...and C.) rarely if ever have any baffling.

This time, I plan on using interior mounted ABS (a black plastic) tanks as they impart no unwanted flavor to the water, are baffled and are algae & mold resistant. The only ones that seem to be on the market unless you spend big bucks to have one custom made are from Valterra and are limited to certain dimensions. They are all 8" x 16" x whatever length which can make for limited applications. In my case, I will be using three 12 gallon tanks conjoined to yield a 36 gallon system. Plenty for my solo use.

ABS Water Tanks Archives - Valterra.com | Valterra.com

The ABS is also much easier to work with in that you can use ABS cement to install hose connections and such where the polyethylene can only be "spin welded" and the joints are commonly prone to leaking if not professionally installed.

I have my "City Water" and "Gravity Fill" inlets which will both have inline filters and will back them up with another pre-pump filter. There are a host of other fancier filters, but I believe I can get by with these since the majority of my drinking water will very likely be bottled and hope to only occasionally rely on local city water for that purpose since it varies so greatly around the country in terms of quality.

Mind you, this will be a very simple system consisting of a single kitchen sink, a hand-held shower and one outdoor connection (very handy for cleaning off muddy boots or whatever else you don't want to drag inside). The internal & any external plumbing will all be PEX lines which also does not impart taste and has a good measure of freeze resistance. I am still shopping water heaters but leaning towards a tankless unit since they conserve a great deal of propane. I am even thinking about having a second, electric water heater for the occasions when I might have the necessary 110v hook up such as you find at RV parks and some campgrounds. That would free up extra propane for cooking (I still prefer fire for that..it's a primal thing).

I welcome any ideas, thoughts or plans you all might have regarding this very basic need.

Another item to consider installing on the incoming fresh water line is a pressure regulating valve. From what I have read on various rv sites you should have one on the incoming line to prevent overpressure of your system in case the city supply (or well water) is at a very high pressure.
 
I will let you guys know what algae growth in my tanks is like, I didn't drain them completely before parking the bus last August. I will be seeing my bus in a week, and I have LDPE tanks that are translucent and let light through. Plan is to drop the tanks and clean them cause I'm sure they are nasty haha.

Those tanks were $85 each for 42 gallon units and I bought 4, free shipping. I got them off ebay. They aren't very rigid but they have threaded bungs on them and get the job done. 36 gallons won't last as long as youd think, but if that works for you then you do you.
 
Also, if you get a pump that's good enough, water pressure is great. I got a pump off Amazon, like $50 or so, and it makes 55 psi easy, and as long as youre not running the shower and sink at the same time the pressure is great, FWIW.
 
I was able to salvage all the tanks from an old coachmen that fit perfect behind my rear axle 35- black,35-grey,65-fresh. They were loose in my frame so I insulated with 2"thick poly-iso rigid board with foil backing board (also salvaged from my work) which made them tight enough I had to use sheetmetal as as a skid plate to re-install(tight fit) in the frame of the bus and my support framing is just as tight but no baffles and for now I don't plan on running with anything in the drain tank but I do want to head out with a full water supply from my house. No baffles in that tank either and haven't been on the road like that yet but in my bus I don't think it will even be noticed?
And with a trailer hooked up I know it won't be.
Filters are a definite and I had a damn good set-up from a RO job I did (sorry reverse osmosis job) until I priced the filters to replace?
Any kind of plastic tubing definitely needs a PRV(pressure reducing valve ) and not to be confused with a PRV (pressure relief valve that should/NEEDS to be on every water heater)sorry steam fitter by trade and a long story there?
I used all hard copper for my build because I was capable and had full access to it and all appurtenances at the time.
Just like wire (don't use soft copper water piping) use stranded wire not solid. The more you bend (vibration) soft copper the harder it gets and will eventually break just like using solid wire verses stranded.
My water tanks are solid and a little lower than what I wanted? But there was a discussin before about the plastic weld spin in fitting's that makes me want to attempt a plug and raise on mine? Other wise I will just build a 1/4" steel skid plate to protect them.
My wife's family has a little chunk of hunting land in MONTELL,TX that has a 5' river to cross 20-30' past the bump gate and the Jolly Roger is going to be there before they give up (even at 49 mph) they are 80 plus and he has retired twice as an oilfield welder including offshore out of corpus and put me to his test when I came home with his granddaughter 15- yrs ago and offered me a truck and all (tough man and a tough way to spend my first vaca in 10-yrs ) couldn't walk away from the boss I had in NC then? Still stuck in N.C. But getting closer to going home TEXAS.
 
Wrapping the translucent tanks in insulation and a heater panel would solve the algea and freezing in cold weather problems in one go.

I think a lot of plastic taste comes from cheap rv fixtures, and the filler hose. You might consider an ozone injector if you are sensitive to water taste.

Having a provision for both city pressure and gravity fill would be smart I think.

Look into the capacitive tank monitoring systems. They are just peel and stick on the side of the tank no holes.
 
i used the translucent tanks and pex plumbing in my build. cant say i have ever noticed a plastic taste to the water.

my water tank is tucked under a bed and only gets indirect light when i open/close the door. the rest of the time its in the dark. no algae in a 3 years use.

i like the translucent, only for the fact that you can see the water level. handy when filling and handy while camping to gauge your water use. i have no tank gauges.

i carry about 50 gallons water when full.
 
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A little food grade hydrogen peroxide will keep your tanks from smelling like a fish tank.

Beyond that there are some goldfish you could drop in the tank to eat the algae, but this method has it's own problems.
 

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