Anybody Ever Install A Reverse Osmosis Unit In Their Rig?

[Foto-n-T]

Given the fact that we're spending the majority of our time in our 5th wheel I've taken to customizing it to suit our needs a little better than the factory.  Items like an inverter to make boondocking more civilized or a accumulator on the water system to absorb pressure shocks etc.  My latest little brain storm stems from the fact that we are currently in Lake Havasu City AZ where if you were to drink the tap water you would have to chew it BEFORE you swallowed.  The RV park that we're in has an RO water machine very close by to our space but it got me to thinking....

On our sink is a water spigot that is connected to one of those cheapy 5 micron inline filters, we don't use it so it pretty much just takes up space.  I'm wondering if any of you have ever installed a Reverse Osmosis system in your rig.  There is one on the market that I've found that uses the fresh water tank as the holding tank but that seems a little extreme.  I'm thinking a residential unit that holds 1/2 to 1 gallon in a pressure tank for drinking water basically.  I like the idea of having the entire fresh tank filled with RO water but that presents the problem of stopping the flow when it's full, meaning that a float valve would have to be installed in a tank that is mounted above my triple axles in a 4-season rig, it's not someplace I want to explore shall we say.

By the way, I do have a 5 micron filtration system built into the city water inlet, this is also used to fill the fresh tank.

 

[JerArdra]

Not in a MH but we have two of them in our house (kitchen and master bath). 

One minor problem in a MH is that for  every gallon or RO water made the RO unit dumps almost 3 gallons of waste water.  In other words it takes "approximately" 4 gallons of the water from your fresh water tank to make 1 gallon of RO water.

Each of our units has 4 filters total and a 2-1/2 gallon holding tank of RO water under each sink.  The capacity of each RO unit is a maximum of 25 gallons a day.  In a MH I would think that 10 gallons a day maximum would be adequate if used for drinking water. 

JerryF

 

[Foto-n-T]

Since we do a fair share of boondocking I wouldn't set it up to RO from our fresh water tank.

The waste water wouldn't be an issue when on full hookups but I do understand that you waste more than you produce.  I'm just tired of lugging one gallon jugs from China-Mart into the rig and besides I get bored and have to tinker with things from time to time.

The other thing that just occured to me is that we have to winterize once in a while if we leave Wyoming later than this year.  Winterization with an RO system might get a little more complicated.

 

[Betty Brewer]

We installed a one gallon RO unit below our sink.  Works very well, but as stated uses lots of gray water space so we use it sparingly.  I have had good luck with our Brita ultramax water filter jug.  It is about 2 gallons,rectangular shaped with a bottom spigot to dispense water.  We filter all drinking water and coffe water using it.  It seems to takeout particles and bad taste well.  I am a fussy water drinker and we no longer purchase water in bottles.  It sets on the floor of the shower when in transit.  When parked, it sits on bathroom counter.  I always have good water for my vitamins.  Filters do not require very frequent changing, but are easy to do when needed.

I have no stock in Brita!

 

[ArdraF]

Joe,

What you refer to as a "cheapy inline 5 micron filter" at the sink can be replaced.  In our RVs we use Everpure ADC cartridges that filter to 1/2-micron.  This level of filtering removes such bad stuff as giardia and cryptosporidium.  Neither of us has ever gotten sick using these filters.  Even in Mexico when half our group got sick, we drank our filtered water and were just fine.  You should have other filters for water entering the RV to remove larger dirt particles so the 1/2-micron unit doesn't get clogged.  They generally recommend two filters to eliminate successively smaller particles, such as a 10 micron at the campground incoming water faucet and a five micron filter inside the motorhome.  Then you can use the better 1/2-micron filter at the sink for drinking water.

In all honesty I have to say we usually have a 2.5 gallon container of a good tasting RO water onboard because there are certain parts of the U.S. that have such bad-tasting water that even good filters won't help improve the taste.  But changing your filtering system to a better one should cut down significantly on the purchase and lugging of those big water containers while making sure your family has safe water to drink.

ArdraF

 

[harleyray]

Joe,

I have experience with both whole house and under counter. The under counter units waste about 5 gallons for every gallon they produce. Our whole house unit wastes 1 gal for every gal it produces. Ours fills the fresh water tank with ro water. I have it plumbed so the waste either comes out through an air fitting so I can use an air hose to direct the water to a nearby bush, or I can direct it into the sewer hose to go down the drain. There are better under sink units that store in a small tank and only waste 1 or 2 gals per gal. Go to rvwaterfilterstore.com, they are very knowledgeable and very nice people. You can call and talk to the owner also.

Ray Down

 

[Ned]

If you route the excess water from the RO unit back to the fresh water tank, it won't go to waste.  It gets used up for showers, dishes, the toilet, etc. and replaced with city water to be processed by the RO unit.

 

[Cant Wait]

One point not mentioned is the water pressure required to "push" the water thru an RO unit. I don't remember the press required, only that we has a counter top RO unit and the press here at home was bearly enough to push the water tru the unit.

 

[Luca1369]

I used an RO unit on my sailboat for many years.  They are expensive.  If all you're using it for is a gallon of drinking water every so often, you'll save a LOT of money just buying some quality bottled water.  Also figure on the cost of cleaning the membrane every so often as you're likely going to have to "pickle" the unit when you prep your RV for the winter.  If you're using your RV every week or so you shouldn't have to worry about this too much (check your instruction manual though).

 

[rvpuller]

I installed one about 6 years ago, I used a household 2 gal unit. I can dump the drain water into the grey tank when we are setting still with full hookups and run the drain water on the ground if we don't have sewer hookup but water. We would never be without it again, we bank water into gal jugs when we are going to be dry camping.

Denny

 

[Foto-n-T]

What you've got there Denny is just about what I'd like to do except I'd probably try to find a smaller tank.  Although....behind our main kitchen drawers I do have quite a bit of dead space, the drawers are a lot shorter than the cabinet that they are in leaving quite an open area behind.  Personally I would love to be able to fill my fresh tank with RO but it presents some engineering issues that I'd rather not delve into, my wife swears I'm related to Rube Goldberg once in a while.

One thing that has presented itself in this discussion is the fact that the membrane might require more curb pressure than some RV parks have at the post.  We use a diaphram type water pressure regulator which I keep set at between 45-50psi which in a lot of places has it running wide open.  Have you had any issue with insufficient input pressure to operate the system or is that a non-event?

 

[Liza]

We have an RO unit in our motor home.  It does the entire coach - fresh water tank.  We have never had a problem related to low pressure. 

 

[harleyray]

We use a boost pump for the ro unit. It puts out about 100psi. Membranes last longer with higher pressure. Entire unit was only a few hundred dollars from rvwaterfilterstore. We have autofill for our fresh water tank, uses a float switch. No more water spots as ro water is all we use.
Ray

 

[Foto-n-T]

We have autofill for our fresh water tank, uses a float switch.

Doesn't installing a float switch involve actually finding and being able to see the fresh tank??

 

[harleyray]

yes you have to find the tank to put a float switch on it.

 

[rvpuller]

What you've got there Denny is just about what I'd like to do except I'd probably try to find a smaller tank.  Although....behind our main kitchen drawers I do have quite a bit of dead space, the drawers are a lot shorter than the cabinet that they are in leaving quite an open area behind.  Personally I would love to be able to fill my fresh tank with RO but it presents some engineering issues that I'd rather not delve into, my wife swears I'm related to Rube Goldberg once in a while.

One thing that has presented itself in this discussion is the fact that the membrane might require more curb pressure than some RV parks have at the post.  We use a diaphram type water pressure regulator which I keep set at between 45-50psi which in a lot of places has it running wide open.  Have you had any issue with insufficient input pressure to operate the system or is that a non-event?

We have used ours down to 40 psi without any problems, it just doesn't make as much water at the pressure. Filling the fresh water tank would take to much hassle for what you would gain.

Denny   

 

[Dutch and Di]

We too have a whole house R/O system in our 5th wheel.  Dutch installed in himself which did save a boatload of money.  They have come down quite a bit in the 8 years since we bought ours.  Wouldn't be without it.  Not only for drinking water but water spots, cleaner clothes since we have a washer and dryer on board and sparkling dishes and glasses when we run our dishwasher.
When we boondock, we go in with a full tank of water and if needed we go to one of those water huts and take on water running it through the 3 filters but not the r/o filter.  Would never be without one.  Hugs, Di

 

[Foto-n-T]

1st of all I'd like to say thanks to those of you who have posted suggestions, ideas and comments.

Okay here's what I'm thinking....

I'm going to cruise Lowes and Home Depot when we get around a city and see what kind of parts I can put together.  I'm not ruling out using a pre-manufactured system but since they're designed for residential homes they might not fit my application all that well.  If I find one that has the appropriate size tank (1 gal?) that would be great.

During the installation of the system I'm going to put an isolation valve onto the in-flow for the RO system so that it can be shut down when we are on pump.  Additionally I think that I'm going to "T" into the fresh water tank vent and also put a valve on that "T" so that if I want I can simply open the valve and let the RO system fill the fresh tank via the vent line.  This will allow us to use RO for showers, cooking etc and would suppliment the little one gallon accumulator tank.

My only issue with this train of thought is how to NOT over fill the fresh tank.  I really don't have any desire to pull the belly pan on this rig and actually do surgery on my fresh tank to install a float valve, way too much work there I'm afraid.  I'll figure something out.

 

[Lou Schneider]

Find someone who knows some electronics and modify the tank level indicator.  It should be fairly simple to couple the voltage driving the "full" LED into a relay that controls a valve to turn the tank's RO feed on or off.

 

[boatbuilder]

If you have a cabinet above the fresh water tank you could use a marine access plate to access the top of the tank.  These plates mount in a hole and either screw in or have a T handle to open them.