What is the best water purifier?

Dear Dave,
We are planning a few long trips in our Grand Design Imagine. I want to get a water purifier to use at the water source at our site. Can you talk about which brand/style works best? Thanks. —Leigh

Dear Leigh,
There is a difference between a water purifier and a water filter. Let’s start by talking about the condition of the water at a campground. Most campgrounds will have a well rather than a municipal water source, so they are required to conduct a certified water test once a year and post a Safety Data Sheet (SDS) (formerly MSDS – Material Safety Data Sheet) in the campground office. This test does not show what minerals and other components are in the water such as rust, lime, calcium, magnesium, zinc, and others.

Testing the water

I highly recommend testing the water with an Intellitec water purity tester that will show the parts per million and will identify minerals, inorganic chemicals, and other harmful contaminants.

This does not actually identify the specific components. However, you can get a more accurate test from most home improvement stores that have more than 17 different tests.


If you are planning to do a lot of dry camping or remote camping, you will also want to get an Arsenic Water Test Kit like this one.

Once you know the water quality is OK, then I recommend a filter to reduce the amount of rust, calcium, and lime that can get into your plumbing system and clog the water pump screen, pump, and faucets. There are several types such as the in-line version from Shurflo.

I use a water reducer on the faucet to limit the pressure to 40 psi so I don’t have a flooded RV the next morning. Another option is the residential version that can be purchased at any home improvement store such as this Omni version. This is what I use so I can replace the cartridge for just a few dollars rather than the entire canister. Our campgrounds have really hard water and literally get packed with what seems to be sand rather quickly.

Another option is a portable soft water conditioner that I have seen used at several campgrounds.

Water purifier vs. water filtration

The before-mentioned devices are all just filters and not necessarily water purification systems. Most filters are rated at 100 microns or not at all. They are designed to filter out sediment and some minerals. Water purification system filters are rated at 0.5 microns and some even lower that will filter out bacteria and viruses.

There seems to be a fine line between water filtration and water purification. According to our local water treatment plant technician, true water purification can only be accomplished by boiling, disinfecting (such as using a chemical introduction such as bleach or iodine), and reverse osmosis.

I personally have only used the filtration systems but have seen many RVers at campgrounds using a variety of systems such as portable reverse osmosis units. One product that I ran across recently is called Clearsource, which is a filtration system that has a 0.5 micron and 0.2 micron filter. I have not had the opportunity to test it as we are below freezing and even close to zero degrees here now. But I’ll test some local campgrounds and lakes when the weather gets nicer.

Let’s open up the discussion to our readers on what they have used in the past. Oftentimes it will depend on where you are going and how much room you have to store the equipment in your rig. Let us know what you are using in the comments below and over on my forum.

Dave Solberg is a leading expert in the RV industry and author of the “RV Handbook” as well as the Managing Editor of the RV Repair Club.

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