Water is water, right? Well, as it turns out, that’s not necessarily true. Some water, described as “hard”, is filled with minerals like lime and iron, and they can be tough on the skin and on your RV’s plumbing system, even destroying certain appliances. When you’re never sure what your water source will be, either at campgrounds or from water fill stations, being prepared with an RV water softener can be very helpful.
In this post, we’re talking about RV water softeners – what they are, how they work, and how they might benefit some RVers.
- 1) What is an RV Water Softener?
- 2) How Does an RV Water Softener Work?
- 3) Benefits of Using an RV Water Softener
- 4) How Long Do RV Water Softeners Last?
- 5) Is it Okay to Drink Softened Water?
- 6) What to Look For in an RV Water Softener
- 7) What is the Best Alternative to Softening Water?
- 8) Do You Need an RV Water Softener?
What is an RV Water Softener?
An RV water softener uses a process called “ion exchange” to soften hard water. Ion exchange replaces hard-water chemicals such as lime, iron, calcium, and magnesium with sodium ions.
In certain regions, high levels of magnesium and calcium can leach from limestone into the groundwater, making the water “hard” and creating a bad taste in the water.
Hard-water chemicals are all capable of accumulating in your RV’s plumbing system, possibly damaging the system and reducing the lifespan of its components. They can accumulate in pipes, fixtures, and your water heater. You may actually have seen evidence of concentrated minerals in your RV showerhead, or in rust staining in your sinks or toilet.
If this is the case, and especially if you spend a lot of time in areas where the water is hard (such as the Desert Southwest), an RV water softener could help.
How Does an RV Water Softener Work?
If you’ve ever seen an inline water filter like the one we show in this post, an RV water softener works in a similar manner. The water softener connects outside your RV, between the water source and your RV’s water inlet. A form of resin inside the housing acts as an attractant for the unwanted minerals in the incoming water.
As water flows through the softener, ion exchange occurs in the resin… replacing the “hard” minerals (calcium, magnesium, and some iron) with sodium chloride. The resulting output water is now “soft” and continues into your RV’s plumbing system.
When the salt ions in the water softener have been used up in the ion exchange process, the system can be reset using a process called “regeneration” where the resin is re-saturated with the salt ions and flushed of the other minerals it accumulated during use.
Benefits of Using an RV Water Softener
The greatest benefits of using an RV water softener are felt by your skin, your RV’s plumbing system, and your RV’s water-related appliances.
If your RV water heater is damaged by calcification of accumulated minerals from hard water, for example, you could have an expensive repair on your hands – or quite possibly a water heater replacement. The same is true of other RV appliances from washers to coffee makers. Pipes and faucets can also be damaged from the build-up, and the flow of water impacted.
Hard water can damage RV appliances that use water, including coffee makers, clothes & dishwashers, and even your RV water pump if your fresh water tank is filled with hard water.
Hard water also reduces your soap and other cleaners’ ability to properly foam up. So you may notice that your soap or shower gel doesn’t suds up as much, your dish soap doesn’t seem as foamy, or your laundry may come out looking dingy (and feeling coarse/rough from the minerals left behind).
Moreover, hard water dries out skin and hair, and everyone knows how miserable an issue that can be. Using a water softener can also improve the taste of your water, and keep mineral deposits in showerheads and faucets, and rust stains in your sinks and toilet bowl, at bay.
How Long Do RV Water Softeners Last?
Portable water softeners themselves are said to last anywhere from 5 to 15 years, but this depends greatly on the hardness of the water being treated, as well as how much water is being used, both of which influence the number of times regeneration occurs.
Some RV water softeners allow for replaceable resin. This means that if the resin needs to be replaced after 5-7 years, new resin can be added that will extend the life of the water softener system for another 5-7 years.
RV water softeners can (and should) be back-flushed every few months for about five minutes to help remove the accumulated “hard” minerals and to keep the system operating effectively. Failing to do so will shorten the lifespan of the water softener. Instructions for the back-flushing process accompany most water softeners.
Is it Okay to Drink Softened Water?
While it’s okay to drink water from a water softener and millions of people drink softened water every day, there are a few things you should know.
Regularly drinking water that passes through a water softener is not recommended for folks who are on a low salt diet for health reasons, or for pregnant or nursing women.
Softened water contains slightly more sodium than unsoftened water and is demineralized to a degree. The amount of sodium in the softened water will vary, depending on how “hard” the incoming water supply is. Therefore, if you are on a low-sodium diet for medical reasons, or if you are a pregnant or nursing woman, it’s advisable to consult with your physician.
What to Look For in an RV Water Softener
The first thing you’ll want to consider is the hardness of the water you’ll be softening. That can be tricky for RVers if they move from place to place. A water test kit like this one is useful for determining water hardness – (50 test strips come with this kit, and results are shown in about 30 seconds):
Typically, when shopping for a water softener, you’d calculate at what capacity you’ll need your water softener to perform. Here’s how that would work:
The level of “hardness” of water is measured in grains per gallon (gpg). The rated capacity of a water softener is the maximum number of grains of water hardness the unit can remove before regeneration must occur.
You’d want to consider the number of people who will be using the water from day to day.
In a house, for example, each person uses an average of 80 gallons per day (YIKES, that seems like a LOT!). In an RV, you should (hopefully!) calculate significantly lower usage than that (for example, when we’re in “extreme boondocking” mode and are trying to extend our fresh water supply, we typically use about 6 gallons of water per day… or about 3 gallons/person per day).
So, you’d multiply the number of people using the water regularly by your calculated daily usage per person, and then multiply that number by the grains of hardness in your water. This would determine how many grains need to be removed daily. You would then purchase an RV water softener that would handle that load.
That would be the technical way to calculate the capacity you’d want to buy.
Most four-person sticks-and-bricks households use a 33,000-grain unit (for an 80-gallon per person average). An RV likely requires a unit of roughly half that capacity.
So, a four-person RVing household would look for around a 16,000-grain unit and a two-person RVing household about half of that.
Leaving the technicalities behind, you might want to consider which units are most popular and most highly rated among RVers.
This 16,000-grain unit is the largest compact RV water softener on the market. It supplies 40% more softened water than any other unit available and takes about 30 minutes to regenerate using two boxes of table salt.
It’s a very popular, highly-rated water softener that uses a standard garden hose connection between the campground’s water source and your RV. It’s also compact, and requires no tools or electricity.
- The Double Standard Softener & Conditioner produces twice the gallons compared to the standard model and is the largest compact RV softener on the...
- Built for the owner of any RV/Marine model, this 16,000 grain unit is a perfect fit and supplies approx. 40% more soft water than any other unit on...
This 8,000-grain unit would be sufficient for a smaller RV with fewer water-related appliances or fewer RVers in the household:
- Removes Dirt, Paint, Rust, And Scale
- Package length: 7.0"
Neither of these units requires frequent regeneration, each uses a box or two of common table salt for the process, and both are reasonable in terms of price and footprint (size and weight).
All of these things are important to consider when shopping for an RV water softener.
What is the Best Alternative to Softening Water?
As an alternative to an RV water softener, you can choose to deal with calcification (if it occurs) by descaling your appliances. For example, you can descale your RV water heater by using white vinegar.
You can also use a product like CLR in appliances like RV washing machines and dishwashers, or to remove scale from shower heads and faucet aerators. (Unfortunately, you can’t descale your RV’s pipes with the same method.)
- CLR Calcium, Lime & Rust Remover - 28 Ounce Bottle
Or, if you’d rather use something less harsh (and/or more readily available), you can use white vinegar as a descaler on your plumbing fixtures and appliances.
Do You Need an RV Water Softener?
The answer to this question really depends on the sources of the water you bring into your RV’s plumbing system, and whether or not you’ve got a problem with “hard” water.
If you tend to be static in – or spend a lot of time in – an area where the water is particularly hard (such as the Desert Southwest, parts of Florida, Wyoming, Montana, Nevada, and others), you may want to consider adding an RV water softener.
However, if you’ve been traveling for some time and your manner of RVing hasn’t raised concerns for you such as mineral build-up in your shower head or sink faucets, or evidence of rust in your sinks or toilets, you may not need a water softener at all.
If you have experienced some or all of these issues, grabbing a test kit to see how hard the water is in the places that you frequent, might be a good idea.
If you’ve been dealing with issues like these, it’s good to know that there may be a solution at hand in an RV water softener.
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Tom
Wednesday 12th of November 2025
Hard water will clog up tankless water heaters so they will require descaling regularly. That isn't a simple thing to do and might require removing it. That's why I use a water softener.
Bill
Wednesday 12th of November 2025
What about the none sodium water softener systems that use citrus and other methods.
Jackie
Sunday 9th of March 2025
We have a water softener as it seems the water wherever we go, even at home, is hard. What I have found and would love a solution to is the water results tends to taste too salty. Would pellets work better? Lite salt??
Jay
Wednesday 12th of November 2025
@Jackie, I'm not sure what pellets you are referring to other than salt pellets. Yes, you can theoretically use Lite Salt, but it is potassium instead of sodium salt. It will taste worse than sodium salt and if you have decreased kidney function (and a lot of older RVers do), that could cause your blood potassium level to rise to dangerous levels, even to the point of stopping your heart.
With water softeners, the amount of salt in the water from the softener will increase with the hardness of the water. If the incoming water quality is soft to start with, you might not have very much salt coming from the softener. In our travels, it was uncommon to find soft water and when we did, that meant that the softener wouldn't need to be regenerated while there. There is no way to filter out the minerals other than with a reverse osmosis (RO) system, and I'll discuss that.
We have a water softener in our house with a well and, as I wrote below, it's automatic and runs off of 45 pound bags of salt pellets that have additives to help preserve the life of the exchange resin. The salt reservoir in it will hold about 4-5 such bags and will last us a long time, several months. The entire house gets this softened water. In our kitchen, we have a RO system under the sink. It takes up a lot of room there, competing with the garbage disposal. The output of the RO system is stored in a low pressure (8 PSI) tank that's about 4 gallons in size. It can only store about 2 gallons of almost pure water. While how RO works is outside of this article, it does use a LOT of water. Being limited to 2 gallons, and it takes about an hour to make a gallon, means that we store extra water in used milk jugs in case something happens to our well. RO in an RV would be possible but very impractical, wasting water and filling up your holding tank just for a couple of gallons of pure water. RO systems have filters and a semi-permeable membrane and without a water softener feeding it, those filters and membrane won't last very long. They're also expensive. In our house, the filters last about 6 months and the membrane a few years.
An automatic system in an RV wouldn't make sense because of their size and weight plus the requirement that they be connected to a water source all of the time. They work by you first determining how hard your house water is and programming that in. It knows how much resin it has and how long it should last by just counting the gallons used. It will determine your average daily usage and if you have enough charged resin left, it won't do anything. If at the end of the day (ours is set for 2 AM), it determines, say, that it has 40 gallons left of active resin and your usual usage is 50 gallons, then it will automatically regenerate at the set time, which takes a bunch of hours, usually when we're sleeping.
With a manual RV system, they're smaller, lighter but you will run out of softened water when not expecting to. They all run off of plain table salt. You can't easily measure how much water you're using, especially when hooked up and every campground's water will have different hardness. Using hard water when the resin is used up until it's convenient to regenerate is what everyone has to do. Of course, you can regenerate before the resin is depleted without doing any harm other than wasting some salt. We have a 10,000 grain system, I believe, and that will last us about 5 days in the RV. It uses just 2 pounds of salt. We once stayed at a campground just outside of Denali NP (in Alaska) before we had a water softener. The water there was so hard that I couldn't rinse the soap out of my hair. I had to used warmed up, distilled water.
We wash and brush our teeth with the soft water in our home and RV. But it's healthier not to drink water with all of the salt. Our solution might not be what you will want to do, but we have a small, countertop water distiller. They come in different wattages but are limited to about 1500 watts, so you would need to be connected to 120V to use it. It will make a gallon of water in about 4 hours or less. It can heat up your RV. We store about 5 gallons of water in milk jugs and start the distiller when we're down to about 2 gallons. The distiller needs to be cleaned out after each use. Putting in about 1/8 tsp of Lemi Shine in the water to be distilled makes that unnecessary. The countertop distiller needs to be stored somewhere, of course, and so does the water. The distiller has a fan on top and you will hear it working. That solution has been working for us for decades. Like I said, there are no filters that will remove calcium and magnesium from your water and neither will magnets. The water softener will also remove heavy metals like lead and arsenic, which is a side benefit. Of course, you can also buy distilled or bottled water fairly easily, but having a distiller means that we don't have to locate a store near where we are camping. I hope this helps to answer your questions. Forgive the long answer, but I'm trying to anticipate additional questions with this.
TheRVgeeks
Sunday 9th of March 2025
Hi Jackie. First, check out Jay's comment just below yours. He has some good insight into the proper way to recharge one of the portable water softeners. The next thing we'd recommend is contacting your water softener manufacturer. Our guess is that they'd have some suggestions on the best way to reduce the taste of salt... because when a water softener is working properly, you shouldn't notice the taste at all (although we're all different, so maybe you just have extra-sensitive taste buds?!).
Jay
Wednesday 13th of November 2024
If you have a water softener in your home, it has a computer and regenerates automatically. That process usually is set to occur while you are sleeping, but if you run out of soft water during the day, while the unit is regenerating, should you use the water, you are contaminating your hot water tank with hard water.
RV water softeners are MANUAL systems. When all of the salt on the resin gets consumed, you suddenly have hard water and can often feel and see the difference immediately. This occurs with no warning.
I found that the regeneration instructions for my unit were incorrect with a very short time. The resin needs to soak in the salt solution for at least 30 minutes and the longer the better. You will want to rock the softener back and forth intermittently to help it. A good time to regenerate would be when you're driving since you're obviously not filling your unit with outside water and the softener tank will be getting agitated.
Your softener will require a certain amount of salt, usually table salt without iodine. Our softener takes 2 pounds, not salt pellets, just plain table salt. The larger the softener, the less often you will need to regenerate. We weigh the salt and store it in Ziploc bags inside the vehicle. You need to dump out at least 2 cups of water (without losing resin) to make room for the new salt. Getting the new salt in is difficult because the opening is now wet and the salt cakes up. I use a thin, wooden dowel to break up the salt clogs in the funnel and the top of the unit.
The final step in the regeneration process involves rinsing out the brine. That can take 20-30 minutes.
Filling your water tank with softened water involves connecting the pre-filter, the hoses to and from the softener, and the fill rate will naturally be slower than without a softener. This may make it less practical to use at a water filling station as opposed to a water hookup at your campsite.
Even a so-called permanently installed system requires removal of the unit in order to recharge and regenerate it. Most RVs won't have the space and/or plumbing access to do that. For most of us, that means leaving the unit attached and unsecured outside the coach. They're not cheap and I do worry that it could "grow legs." Using a water softener does add to the hookup time when arriving at a new campsite.
Bill Scott
Wednesday 13th of November 2024
We are full timing in a fifth wheel. Our skin was drying up and we were dealing with water stains everywhere. Purchased the "On The Go" 16,000 unit and would not consider going back. Our skin and rig plumbing make the investment well worth it!