Reverse Osmosis System Installed

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Well-known member
Jan 1, 2012
Cody, Wyoming - Sometimes
A week or so ago I posted a thread regarding installing an RO system in an RV.  After taking the responses to heart I was wandering around Lowes and came across a Whirlpool RO system for $147 that had a small 9"x14" pressure tank with the kit, it came home with me.

The installation was pretty straight forward with one exception, the drain system contained in the kit wasn't compatible with the drain stem coming from the kitchen sink.  The solution was to drill a 3/4" hole in the sink drain pipe above the P trap and thread a 90 into it that had a 3/8" compression fitting compatible to the kit drain system.  To feed the system with fresh water I used the output to the small spigot on the sink that originally had a 5 micron filter on it, we never used it anyway.  That spigot was replaced by the RO output so it was a win-win situation although I did have to open the hole in the sink and counter to 1 3/8" instead of the original 1/2".  To facilitate boondocking I did install a valve on the water input to the RO system so that it can be easily disabled when we're not on full hookups.  Originally I thought about dumping the RO water into our fresh tank and using it in lieu of a pressure tank but after using the kit storage tank for the last few days I'm not even going to consider the extra work of doing that.

Although the pressure tank does take up some extra space under the sink, the fact that we no longer have between 2 and 6 one gallon jugs of water taking up space in the garage pantry far outweighs the lost storage space under the sink.  It is so much more convenient to simply open the spigot on the sink for drinking water, coffee maker etc.

About the only thing that I can see that might be an issue would be winterizing, I'll probably have to remove the membrane canister and replace it with a dummy to push antifreeze through when I have to winterize.
It's actually pretty hard to get pics on this project.  The RO pre/post filters are on a rack that hangs on the partition under the sink that divides the sink area from the drawers to the left.  The drain that I adapted is just out of frame on the top of the pic I managed to get.

I figure that if I go back up to northern Idaho to log again next summer and do the long term boondock thing I'll still be able to use it since I've got an extra 110 gallons of water in drums on the back of the truck when I'm up there.

I've got to say that even after only using this thing for a few days, I wish I'd have done it years ago.


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Foto-n-T said:
I've got to say that even after only using this thing for a few days, I wish I'd have done it years ago.

That's how we feel about ours in the stick house, installed a few months ago.  We've lived here for 9+ years, refilling gallon jugs of drinking water every few days due to the poor quality of our tap water.  Come to find out, our local Culligan rents RO systems.  $21/month for all the quality water we can use.  ;)  That's about the same amount we were paying (37 cents at a time) for hauling all those jugs to and from the store repeatedly.

Once my rental contract is expired in a year, I may look at buying and installing my own system permanently (although not from Culligan, there's costs upwards of $1000).  I'll be interested in any tips on the most recommended brands/models.
I'm no expert on this but here's my take on it.

The way the RO system works is probably basically the same no matter who the manufacturer is.  It's my understanding that some RO membranes waste more water than others though, I will assume that those that put out less brine water are probably more permeable.  Whether that's good or bad I can't make any comments on simply 'cause I'm ignorant of which is better.

All RO systems use some sort of "pre" filter to get the big chunks out and to neutralize chlorine.  In my case I had already installed a large 5 micron filter to the shore water input.  My thinking is that since that filter also has activated charcoal in it that I should see longer life from the membrane on this system.

I think if I was to do it again my first requirement other than the small holding tank would be comparing the cost of the replacement filters and membranes.  Whirlpool says that the pre/post filters need to be changed every six months.  They also state that the membrane "may" last up to a year (they DO NOT like chlorine).  The pre/post filters are not too pricey but from what I've seen, those membranes are around $50.
Foto-n-T said:
The way the RO system works is probably basically the same no matter who the manufacturer is.

I like the sound of this.  On my current rental setup, I was required to pay for the installation - including all the various supply lines and joints to and from the tank, filters, spigot, and fridge icemaker (I paid extra for that).  Culligan owns the tank, filter assembly, and spigot.  It should be pretty easy for me to eventually return those parts to them and install my own, since all the plumbing will be in place.
It's too bad you're under contract for that thing.  The installation process really isn't all that bad, especially if you're halfway handy with tools.  What I'd do is keep my eye out for sales at the big box home improvement stores as well as on Amazon.  You've got until the end of your contract to shop so to speak and get the best deal out there.

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