We have a Watts Premier zero-waste system, have changed filters once in 12 years.

Examine your actual need for RO. Most people do not need them at all.

Thanks, Sofie. It's for arsenic reduction, and I understand a RO system is the best way to reduce it to below EPA acceptable levels. Do you know of another way?

Our RO worked perfectly for arsenic. Our water source is from a small well company, less than 50 customers for this well. When the standards changed for arsenic a few years ago, the company recommended using bottled water for drinking until they came up with a treatment. That's when we needed to change the filter, when we were using a lot more RO water for a while.

Oh, and our system was only a couple of hundred dollars and my husband installed it under the kitchen sink.

@alesesne,

Living on well water is more complicated than living on a water system. It requires some education and some maintenance to make the well water nice AND safe. Annual testing for nitrates and bacteria is highly recommended. Comprehensive water test for well water from time to time is smart to do also. Well water conditions can change and it does.

There's a lot more to ROs than buying one at Home depot and installing it under the sink.

An important consideration is the quality of water being fed to the RO. RO membranes don't last as long if fed hard water. If there's iron in the water it can foul the filters. Bacteria can colonize in carbon filters in an RO.

ROs can be designed and configured to deal with specific problems, especially with well water, by people who know and understand them but not by corporations that contract for RO manufacture on the other side of the world and simply import, warehouse, and ship boxes.

@sushipup1,

In the 12 years between filter changes ever checked the rejection rate of your RO? That would be how one would know when it is time to change the filters.

Ever sanitize your RO?

I know this will cause an argument but I have used the "el cheapo" Nelsen RO units and found they are good and will do exactly what you want without breaking the bank. I do not recommend any proprietary equipment because of the cost for repair and the fact that you can not get repair parts. I have customers that have had problems with the Watts quick discount filters not allowing water to pass even through they are new filters.

for real? you changed your carbon filters on RO unit once in a decade? most manufacturers recommend 6 months and some let it slide for 1 yr.

My husband assures me that I have confused this with something else, and all is maintained properly. Sorry.

Thanks for the comment about the Nelsen RO system, Biermech. I am still on the fence about the type of RO I am going to have installed. I am not a DIY person, so I am still considering Culligan, but I am increasingly interested in having a local plumbing company install and they use Nelsen. I can find very little about them online -- including customer reviews/complaints -- but they cost half of what the Culligan does. I am finding it hard to justify the extra expense just for name brand. Plus, I would much prefer to use a brand that doesn't require proprietary parts. The sales pitch from each is comparable, but I just want to know that I've got a system that works, is affordable, and importantly -- one that I can easily maintain and regularly replace the filters. I do not want to compromise on quality on the critical components, and I am still trying to figure out if Nelsen would meet my needs. Any specific reasons to justify paying twice the price for Culligan over having my local plumbing shop install Nelsen?

Which ever RO system you choose, make sure it has a TFC (Thin Film Composit) membrane. These are the better membranes.

I got a free used watts system. Been sitting in garage for 1 month. Next to new membrane. Gotta order new carbon filters.