Culligan reverse osmosis water filtration system

[terryV]

My Culligan Man came by today to change my filters in my home reverse osmosis water filtration system. We've had one for 30 odd years and just love the water quality we get from it. We usually fill up a bunch of gallon plastic bottles with the water to take in the Airstream for coffee, tea, iced tea, and drinking water.

Anyway, the conversation turned to trailer camping and the Culigan Man said he was going to put an RO system in his camper. Wow, that would be great. No filling and storing of bottles. No having to buy bottled water.

So, not wanting to jump into something without consulting my panel of experts, I thought I would ask you guys if anyone has done this and if there are reasons not to do it.

Whatchathink?

[dkottum]

Our friends have it in their motorhome so we checked on it. Thought it took a lot of precious Airstream space. We can buy the same water almost anywhere on the road for much less than the system cost for years to come.

[Protagonist]

Reverse osmosis is very wasteful of water. I don't know how much through-put you have when you're starting with basically clean municipal water, but I looked at a system for a deep well at one of our field sites at work. For a typical well-water installation, for four gallons you put into the system, you'd get maybe a gallon to a gallon-and-a-half of treated water, and two-and-a-half to three gallons of wastewater diverted to your septic system. And every so often you have to back-flush the system to clean the membrane (unless you spend the bucks to just replace the membrane), meaning you waste clean water you've already made to back-flush.

Unless you have contaminants in your water that you can't treat any other way, I'd go with some other treatment system instead. The ultimate portable system would be a UV filter, that kills microorganisms by UV light, followed by a Granular Activiated Carbon (GAC) filter. This setup will remove virtually all harmful microorganisms from coliforms to algae, as well as getting rid of most turbidity, tastes, and odors.

About the only contaminants the UV+GAC wouldn't remove would be dissolved metals such as iron. For that you need a manganese greensand filter as well. But if your water was that bad, it would be cheaper to use bottled water.

[terryV]

Wow, that pretty much settles it, then. My biggest concern was winterization, but you have come up with things that I didn't even know about.

OK, this project is dead. Moving on to something else.

Thanks Guys.

[Wayward]

Originally Posted by terryV

OK, this project is dead. Moving on to something else.

RO removes all the nasty stuff from the water not just hardness so the cons stated above should be considered in that light.

Size: Any water treatment will take up space. A compact RO does not take up much more room than a good filter - in fact most of its size is filters.


Water waste: Only a factor if you are using it when not on hookups (dry camping). We have a separate tap for the filtered water and only use it for drinking and cooking. If we use a gallon a day, the cost of 3-4 gallons is well worth the absolute safety of RO. We do not pay separately for water at hookup campsites anyway.

For whole RV usage (not just drinking) I have been thinking about feeding the campsite water into the RO filter, and feeding the RO filter output into the onboard FW tank. Then use the 12v pump to supply all water taps with RO filtered, soft water.

[terryV]

Where do you get a compact RO system? The filter package on Culligan's unit is not so bad, but the smallest pressure tank that they have is still kind of big.

[Wayward]

Originally Posted by terryV

Where do you get a compact RO system? The filter package on Culligan's unit is not so bad, but the smallest pressure tank that they have is still kind of big.

Yes the filter packages are about the same but for more flexible mounting configurations you could also buy the RO membrane canister separately and place only the filters you need somewhere "upstream" of it.


Amtrol makes a 2 gal tank. The RO-2 (8" in diameter")

Amtrol ® RO 2 RO Replacement Accumulator Tank

It does not need a rubber diaphragm inside. You can make you ownpressure accumulator with a section of PVC drain pipe with a cap on it - any size, shape or placement you like.


RV DIY Water Accumulator | ModMyRV

The RV Water Filter Store has parts..
RV Water Filter Store: Standard Filter Canisters for Whole RV

THe RO unit itself looks like this

All the other canisters are filters.

[BoldAdventure]

Originally Posted by Wayward

RO removes all the nasty stuff from the water not just hardness so the cons stated above should be considered in that light.

If you have concerns about fluoride in your water supply such as myself, then RO is one of 3 types of filters than can remove up to 90% of it.

We personally have a Propur water filtration system that is good old gravity based I planned on taking, but thinking about it, it will take up storage space or counter space when in use.

Good info Wayward.

[Wayward]

Originally Posted by terryV

but the smallest pressure tank that they have is still kind of big.

It is worth noting the reason an RO unit needs a pressure tank. The RO membrane only passes a small stream of water through it - not enough to fill your coffee pot very fast.

So the accumulator tank is on the output side of the RO filter. It is a steel tank with a trapped pocket of air. The filtered water trickles in until the air pressure equals the system water pressure. When you open the tap, water gushes out of the tank, pushed along by the air pressure inside the tank.

There is an alternative to the accumulator tank. You can let the RO output trickle into a non pressurized tank like your freshwater holding tank, and then use the 12v pump in the Airstream to supply filtered soft water under pressure throughout the whole trailer. It does require a float valve however to avoid overfilling the tank. RV Water Filter Store sells them as that is how they configure the reverse osmosis for RVs..

I am seriously considering the tank route.

[73 Sov 31]

Saving.

Great info.