This REALLY depends on how it's plumbed, but it's almost entirely plumbed right after the incoming utility feed shutoff valve, making it a whole house deal, hot and cold both. One could consider putting in a hose bibb right there to bypass, which would be EZ-PZ if you are doing the work yourself.

They should be plumbed into the house input line, AFTER the hose bib lines are split off.

Take pictures of the piping and valves going to it and from it and post them. We'll probably be able to tell you.

I think a lot of it depends on when the house was built. I believe all houses past a certain point have the loop preinstalled. If the loop isn't installed when they build the house, it's going to affect all of your outlets (inside and out).

I have a water softener but I added a RO system last year so I could use that water for sensitive plants. You can get a relatively cheap RO system on Amazon that was pretty easy to install.

By the way, this is a shot of my neighbor's WS setup with the tank removed. It was plumbed poorly by a representative of Culligan. There are twelve direction changing fittings on this mess, including the el in the ground coming up from the utility supply line, when there was originally two. Consider what this, and the resistance in the tank, does to the water pressure throughout the entire house and plan your layout carefully

Iandyaz, I purchased the RO system from Amazon too. You say it was easy to install? I'm not so handy. You think it's still pretty easy? It's the Ispring system. Plumber wants to charge $195 to install. Seems like a lot since I already have a filtration system it's replacing.

Yeah, that's the one I got. If you don't mind drilling a small hole in a drain pipe (mine are plastic so it was very easy), then it's easy. It comes with some good installation instructions. I think the hardest part was actually getting under the sink to reach the water outlet (I'm 6'4" and the small doors made getting under there slightly annoying). Just note that when you first install it, the water coming out of it looks bad at first until it runs for a while, I think that has to do with the charcoal filter.

Also, I got a TDS meter from Amazon when I bought it so I can tell when to change the filters (and you can test when the water is done clearing through the filters on initial install). It's also kinda neat to see the difference in the tap water vs RO water (mine was over 500 ppm vs 40 ppm after the RO system).

Ok I'm unpacking it and giving it a go. There's already a filtration system under sink so I hope it will be fairly easy. My projects usually turn disastrous so we will see. I got the TDS meter as well. How long have you had yours?

I got mine in Nov 2013, so almost a year and a half. Still using the original filters that came with it and the TDS meter still shows around 50-60. How'd the install go?

By all means, DON'T water your yard with softened water. Our soils have too much sodium already!!!!! I know what I'm talking about.

Did the RO system install myself. Was actually easy but I made it harder than it should have been. TDS measured between 465 to 495 before and around 26-36 afterwards. Should have done this years ago.