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The Best Marine Water Softeners for 2023

Writen by Ronald Brown

Fact checked by Natalie Bridges

best marine water softener

If it’s your first time buying the best marine water softener, choosing one for your needs can be time-consuming. There are plenty of choices available, so comparing and figuring out which among them is the right one can be confusing. And if you don’t know what features to check, you might not be able to decide which one is better. In this buying guide, you’ll learn about the top marine water softeners and their qualities.

Shopping for a marine water softener is not much different from buying a residential unit. Buyers must be aware of the factors that distinguish the top-tier marine water softener from mediocre ones. Here are three crucial parameters to consider.

  • Capacity: Marine water softeners must remove as much calcium carbonate and magnesium molecules from the water as possible. Manufacturers rate their products’ capacity in “grains.” The higher the “grain” number, the more calcium carbonate the softener can accommodate before needing a recharge.
  • Size: Space is a luxury in most boats. Only super-yachts can opt for full-sized water softeners. Hence, the product’s dimensions become a vital consideration for boat owners. You might want to pick one that sits nicely in the boat’s main water supply line, between the storage tank and the first faucet (or water appliance).
  • Maintenance: Marine water softeners can last many years, but their components require periodic checkups. For instance, the brine tank needs annual maintenance and cleaning, while the resin tank might demand scheduled maintenance by professional every two to three years. Refilling the brine tank with the appropriate type of softener salt is also crucial.

Also, we’ll discuss the features that you must consider when buying this product. If you’re ready, let’s get started with the next section to review the top-tier products.

Top-Rated Products

Best Overall

OTG4-DBLSOFT Water Softener


Honorable Mention

Pro Aqua Water Softener


Editor’s Pick

AO Smith Water Softener


Table of Contents

Top 4 Marine Water Softener Reviews

1. OTG4-DBLSOFT-Portable RV Water Softener

According to different marine water softener reviews, the OTG4-DBLSOFT is one of the most suitable choices. It is convenient, which is essential because it will allow you to transport and easily carry it wherever you go. What’s more, it has a large capacity of 16,000 grains, which is twice as much as the original version.

A considerable thumbs-up goes to this 16,000 grain water softener thanks to its efficiency in supplying you with up to 40% of soft water in just half an hour or even less for regeneration. The time it requires to finish a cycle is impressive, and you can be sure that you’ll have adequate soft water since each cycle produces about 1,600 gallons of water. You can be guaranteed water for the next 40 days.

Another reason why you’d like this is its compact and robust design. It is space-saving, which makes it very convenient to bring along. With its mouth opening, you can easily add more salt. You can also lug it around effortlessly courtesy of its built-in top handle.

What’s more, you will also be impressed with the fact that this is designed for RV and marine owners. It has an inlet hose, and it can be swiveled to 360 degrees, so getting the fittings fixed is easier. It also comes with a road-friendly cap and plug.

Encountering hard water issues when traveling can be very unpleasant, and this water softener is the ultimate solution. It will ensure that all stomachs are in the best health during the road trip. With the best marine water softener, you also help your plumbing and all water-related appliances to have better performance and an extended life span.

You’d be happy to know that getting this all set-up can be a DIY project for you. All the instructions are provided. After the installation and initial flush, you are all set up and the system is all working in the background.

Just a little drawback would be the tendency of some leaks at the fittings, so it would be best to have some Teflon tape handy. Anyhow, it is a must-have for you if you have an RV or a boat. It works like a charm and is easy to set use and install.
What We Like
  • Regenerates in less than 30 minutes
  • Large capacity
  • Space saver and compact design
  • Large mouth design and a 360-degree swivel
  • Installation is easy
What We Don’t Like
  • Some leaks at the fittings may happen

2. Pro Aqua Portable Mobile Water Softener

The Pro Aqua Portable Mobile water softener is a crowd favorite when it comes to effectiveness and affordability. This premium-grade unit removes the hardness in your water even if you are not at home. If you are a travel enthusiast and spend half of the year cruising the roads or the seas, this is a perfect option.

With this unit, you can end your problems of dry scalps, dry skin, and eczema. The Pro Aqua removes all the harmful hard minerals from your water, making it softer and healthier for you, your hair and your skin. Right after the first use, you will already see, feel, and experience the improved difference. The odor and taste of your water are better, lathering your soap is much easier, and the way your dishwasher and washing machine performs improves, too.

The water fixtures and appliances in an RV or boat are not cheap. Thanks to this portable mobile water softener, you can also protect your investments and extend their lifespan. The Pro Aqua is excellent for preventing hard water and mineral build-up and helps deal with the red stains caused by iron.

You’ll be pleased to know that this compact and easy to store system can give you a steady supply of 40% soft water which is way more than what other units can produce. This water softener is designed with portability and stability in mind, which is what boat, RV, and mobile homeowners need.

After installation, this system is ready to be used. There is no wait time or downtime. You can simply give it less than 5 minutes for a quick backwash on the system and for the loose resin beads to be flushed, and you are good to go. It’s fast and straightforward to set up, and it works instantly.

An added buying point for you is that this system can regenerate in less than half an hour with two boxes of salt. You don’t need any other chemicals or unique/hard to find salts. All you need is regular table salt, and this unit can also supply you with 2,000 gallons of water or adequate for the next 40 days.

A minor downside for this water softener unit would be some leaks in a few cases, so it’s better to have a stash of Teflon tapes for those ‘just in case’ moments. This product is a testament to working as it should. It is an excellent and reliable water softener, and you simply must have these in your RV or boat.
What We Like
  • Regenerates in less than 30 minutes
  • No downtime and it works instantly
  • 100% portable and reliable
  • Guarantees 2,000 gallons of water or water enough for 40 days
  • Requires only two boxes of salt
What We Don’t Like
  • Possible leaks

3. AO Smith AO-WH-DSCLR Water Softener

The AO Smith AO-WH-DSCLR is a unique system for treating hard water in marine vessels, homes, and RVs without worrying about salt and its environmental effects.

This product makes its case as a reliable spot free boat wash system. Unlike Watts RV PRO-1000 OR M7002, this device does not use salt to remove calcium carbonate, magnesium, and other hard minerals.

Its salt-free operation process offers an economical option for budget-conscious boaters. I could imagine how much money boaters will save monthly because they no longer have to buy salt bags. Plus, this device only requires an 8.75-inch diameter floor space, making it an ideal choice for small boats.

Installation is also more straightforward than a conventional water softener. I will never worry about setting up a drain line, performing periodic backwashing, and frequently refilling the tank with salt. The convenience families will get from this device is unparalleled. In fact, this unit should be an excellent replacement for my Clack.

Its calcium and magnesium filtration capabilities are equally impressive. The semipermeable membrane can accommodate 600,000 gallons of hard water. The brand’s six-year warranty also gives further peace of mind that the product will be able to last for quite a long time.

I must emphasize that a water conditioner is NOT a water softener. Although I commend the brand for putting “water softener alternative” in its marketing information, some folks might think this product removes calcium and magnesium in the water.

In addition, this product does not remove iron, sulfur, and TDS, which explains why some users complain of a “weird” taste in their drinking water.

Still, it should not be an issue for families who want to rid their marine plumbing systems and water appliances of limescale. And this product surprises even hardcore water softener lovers with its limescale-prevention capabilities.
What We Like
  • Impressive 600,000-gallon capacity
  • Economical because it does not use salt
  • Hassle-free installation and maintenance
  • Space-saving design with a small diameter of 8.75 inch
  • Six-year warranty
What We Don’t Like
  • Some issues with water tasting “weird”

4. Watts RV Portable Water Softener

I’ve been looking for a suitable replacement for the Park Model water softener, and the Watts RV PRO-1000 OR M7002 is an attractive alternative.

Unlike the AO-WH-DSCLR, this unit is a “water softener” that eliminates calcium, magnesium, iron, and other hard minerals in the water and replaces them with sodium. Some might be wary of using salt to “soften” water, but it is the most effective way.

Highly versatile, this salt water purifier for boats can also be used on RVs. It can handle 10,000 grains of calcium carbonate before regeneration. So if my water contains 10 grains of calcium per gallon, I can soften up to 1000 gallons before I have to recharge the ion exchange resin.

Regenerating this product is also a breeze. Twenty minutes and 2 pounds of salt are all I need to continue softening the water in my boat. The top-rated part is I can use ordinary table salt rather than expensive ones. I also do not need to disconnect the system from the boat’s water supply line because of this water softener’s custom-built flow valves.

This water softener might have a wider diameter than the AO-WH-DSCLR (10 inches vs. 8.75 inches). Still, it remains a compact and portable water softener for RV systems and marine vessels. Its decent 4 GPM flow rate is more than enough for a pleasant shower on my boat.

If there’s anything to complain about this water softener, it would be the fact that it can occasionally leak, especially when being transported elsewhere. Because the problem isn’t too severe, I’m more than willing to overlook this minor drawback.

Boat owners who prefer salt-based water softeners can rely on this system to eliminate hard minerals from the boat’s water supply.
What We Like
  • 10,000-grain capacity
  • 20-minute hassle-free regeneration with unique flow valves
  • 4-GPM flow rate without substantial water pressure reduction
  • 2-lb table salt regeneration requirement
  • Portable design of 22 x 10 x 10 inches
What We Don’t Like
  • May leak sporadically

Outdated Products

Mobile Soft Water Softener (Outdated)

As a top choice when it comes to a portable water softener, the Mobile Soft water softener does a fantastic job of softening the water in your recreational cars. You’d find this a worthwhile investment because this unit is more than capable of removing all the lead, magnesium, iron, tannins, and other harmful minerals from your hard water. With this product, you’ll soon enjoy stain-free appliances and fixtures plus a plumbing system without any clogs due to mineral build-up. Overall, with this water softener on board your RV or boat, you’ll have better water quality wherever you are.

Practical and user-friendly, this 16,000-grain capable unit can provide you with a maximum of 5 gallons of soft water in 60 seconds. Imagine how much hard work this system is capable of doing! And its regeneration process is also rapid without needing any electricity.

Apart from being completely portable with an all-natural carrying style, the overall design and build of the mobile-soft water are well thought of. It can adequately handle ½ cubic of high-capacity resins, and it comes with lead-free nylon for its inlet connection. It has also incorporated fiberglass-reinforced plastic to ensure that the pressure level is maintained and consistent. Its reliable nylon fittings are National Sanitary Foundation-approved, which means that it is entirely safe when it comes to the treatment of drinking water.

Setting this water softener unit is a breeze. There are no complicated and frustrating instructions but a system that you can install and be proud of because it 100% works. You will enjoy soft water and its many benefits wherever you are; may it be on land or sea, your soft water will make everything better. You’ll have better-tasting and cleaner water to drink. You’ll feel fresher after your shower. Your small plumbing and pipes system will be happy, too, knowing that the mineral build-up will be lessened if not completely removed.

The only downside of this water softener is it lacks the input water hose connector. It would be more helpful and convenient if it came with the ¾ connectors that RV and marine users typically need. Aside from that, this product promises better water and a water softener unit that is worth your money, and it’s a big yes to both commitments.
What We Like
  • 16,000-grain capacity
  • Lightweight and portable design
  • National Sanitary Foundation approved
  • Solid nylon fitting
  • Installation is easy
What We Don’t Like
  • No input water hose connector included

What Is A Marine Water Softener/ Who Is This For


Contrary to its name, the top-rated marine water softener is not just limited to boats. This kind of water softener is considered as a portable water softener unit. It is casually termed as an ‘on the go’ water softener system.

Just as the name implies, this system’s primary goal is to soften your water and provide you with cleaner and safer water while you are on your recreational vehicle. May it be on land or sea, you can have access to water that is safe for consumption.

These water softeners, like the household ones, are responsible for removing unpleasant minerals like magnesium, calcium, iron, and lime from all of your water. By removing these, the pipes and plumbing system of your boat, RV, and mobile homes are saved from destructive mineral scaling.

What sets a marine water softener apart is its compact design. You can bring it with you conveniently, and it doesn’t take much space either. It is designed to be transported easily and intended to be carried and moved around a lot. Hence, it works without the need for accessories or electricity.

Marine water softeners are highly recommended for folks who incorporate a little outdoor adventure regularly. Those who have mobile homes, recreational vehicles, boats, campers, and RVs should find these units necessary before venturing to the outdoors. Homeowners can also consider having this as a small backup system in cases of emergency.

Having the right marine water softener is a smart investment. Water is life, and soft water promotes an even better experience. Whether you are a homebody or an outdoor enthusiast, getting this unit is a smart, practical, and lifesaving choice.

How Does It Work

What makes a marine water softener unique is its ease of use feature. Usually, you can use the regular garden hose for its connections. The set-up is simple because your typical garden hose will connect your boat, RV, or pressure washer to your local park or dock faucet.

Most units are already pre-assembled, charged, and all set to be used. They don’t require any unique accessories or electricity to work. Connectors may also come with the kit upon purchase. It would be a good idea though to always have a stash of Teflon tape in your RV or boat.

Portable water softeners work the same as the regular ones used in your homes except for their compact design and the fact that you can have soft water anywhere you may be. These units eliminate the harmful minerals from your water by substituting those mineral ions with a different kind of ion like salt.

This ion exchange requires the regular refill of salts so that the process of regeneration can happen. Your water softener will then be able to provide you with cleaner water. Depending on the make and model of your marine water softener, you might need to manually add in the salt to go through its regeneration cycles without continuous interruptions.

Advantages And Disadvantages Of Using Marine Water Softener



Getting a marine water softener is the most reliable way to have soft water even when you are not at home. If you like spending some weeks in your RV and doing a little camping or trekking, then having soft water is highly recommended. It is the same when you spend time cruising on your boat.

Many folks opt to have this system installed on their recreational vehicles and boats because it is compact and proven to take out the hardness in the water. Installation is doable and can even be a DIY if you want to.

Marine water softeners make your water softer, thus safer. Having access to water that is safe for consumption is a must when you are in the middle of the sea or find yourself in an isolated area. Getting a water softener at least gives you a guarantee that your water’s mineral content is balanced, and toxins such as ferrous iron are removed.

It is also cost-efficient because it helps extend the life of your plumbing system and water appliances. These portable water softener units help minimize the build-up of hard minerals on your pipes, saving you the cost of repairs or replacements.

It also extends the vibrancy of your clothes and sheets up to 40%. Since water is softer, you don’t need to be spending as much on laundry detergent, soap, and water. These can be lathered easier and, in general, makes cleaning more relaxed.


Every product has its disadvantages, so do marine water softeners. Some owners of salt-based systems may find the water saltier than their liking, and too much sodium is not good. Water that has been treated is also not recommended to be used for irrigation.

The main reason why people have second thoughts about getting these mobile systems would be the cost involved. It is quite expensive, and the maintenance required must also have its own budget.

Most importantly, marine water softeners do not 100% disinfect water. You might need an additional cleaning mechanism like a filtering system to achieve the safest kinds of water that you can just drink from the tap.

However, the advantages outweigh the drawbacks. A unit is not something that you’d be using for a month or a single year anyway. It is an investment and depends on your need. It is a smart and practical one.

Buying Guide

It may take some time and effort to check and go through some online boat water softener reviews before making your significant purchase. These reviews are based on on-hand experiences, so more or less, you get honest feedback to help you decide before buying. To help you a little further, here are some factors you can consider so you can get your money’s worth and ultimately achieve your goal of having soft water anytime and anywhere.

Size Matters – for an RV or a boat, every available inch is precious, so it is best to go for a water softener that is compact and portable in design. This feature can save you from the impracticality and inconvenience when you need to soften your water outdoors. The capacity of the water softener is also a factor to consider. Make sure that it can sufficiently supply 4-5 people.

Hardness Level – the mobile water softener system you purchase should address your water’s hardness level. It is a must before buying. There are a lot of water softeners you can buy but the system working effectively and giving you clean and soft water will depend on its ability to do so. If your water hardness is exceptionally high, opt for those high-end and premium water filtration systems that can handle it accordingly. You can’t expect a budget-friendly unit to address extreme hard water issues.

Water Softener Type – you also have to consider what kind of water softener you should get. You can opt for the usual salt-based and salt-free systems that are proven to be fully reliable. You also have other choices like an electronic system or a magnetic water softener unit. Each would have its own set of wins and drawbacks. Look into this detail further based on your current water information, as well as your needs and preferences.

Grain Capacity – this is a must-know detail for your future water softener system. The grain capacity dictates how many contaminants and impurities it can get rid of. Commercial units would usually have a minimum of 15,000-grain capacity, so don’t settle for less.

Maintenance – this is a commitment from you. You also must note your system’s preservation needs and the frequency required for its maintenance. Some systems need to be maintained daily. Salt-based water softener systems, for instance, would require you to refill salt pallets regularly manually. A considerable part of maintenance would be the cost to ensure that the unit runs all the time smoothly.

Frequently Asked Questions (FAQs)

How do you soften hard water naturally?

You have several ways to soften hard water naturally without relying on a marine and RV water softener and filter system.

If you are only concerned about hard minerals in your cooking water, you can add baking soda to improve your dish’s texture and taste. This technique is also ideal for shower applications and for pressure washer.

We also recommend boiling the hard water. Allow the boiled water to cool down before scooping the chalky-white calcium residue on the water’s surface. It is worth noting this technique does not remove magnesium, only calcium carbonate.

Another method for “softening” water without a descaler is adding sodium carbonate to the laundry water. This technique relies on sodium carbonate’s ability to dissolve magnesium and calcium, giving you “soft water” for your clothes. However, we must caution you about adding this substance to your plumbing because it can produce scale.

How often should you drain your marine water softener?

The frequency of draining your hard water marine softening device depends on how “hard” the water is or how many grains of calcium carbonate the water contains per gallon.

Most boaters and RV owners recommend draining and cleaning the water softener once yearly, while others suggest a monthly inspection. It is worth noting that draining occurs during cleaning; this also goes for the highest-rated water softener. Hence, it is safe to assume that the draining frequency depends on the water softener cleaning frequency.

Similarly, when you dock, you should also conduct monthly inspections to determine if your water softener needs cleaning. You might also want to look for salt mushing (salt forming a thick sludge in the brine tank’s bottom) and salt bridges (thick yet crumbly salt crusts on the brine solution’s surface).

Smelly and discolored water can also warrant a water softener cleaning. You might also notice you need to use more soap, shampoo, and detergents than usual. Showers might be less pleasant. These signs all indicate a water softener cleaning is necessary. Again, you cannot clean the water softener without draining it.

Where is the most suitable place to install marine water softener?

Marine water softeners should always be in a section of the marine vessel’s main water supply line before the first faucet or water appliance. This arrangement follows the conventional design of residential units.

For example, suppose you have a Camco marine water softener, water heater, water pressure tank, and several faucets in the boat. In that case, the ideal location for the water softener is before the water heater and faucets but after the water pump.

This is because you need the pump to push the hard water forward. Placing the softener before the pump can cause clogging, water pressure reduction, and risk of pressure pump failure.

If there is any place you should not install a marine water softener or any water softener type, that would be an uneven and wet spot. Most water softeners have an electrical system to activate and manage the regeneration cycles, so you’d want to keep them away from moisture.

How long can marine water softener sit without being used?

A marine water softener can sit for a few years without being used and still be functional. However, you might want to understand that its post-idle water-softening performance depends on several factors.

To name an example, did you prepare the water softener for storage before you went on vacation? Any water in the softener tank can lead to ion exchange resin degradation and potential scale formation. That is how these water appliances lose their value – improper winterization or storage.

Also, did you bypass the water softener when it was not in use? Bypassing saves the water softener from potential resin degradation, eliminating the need for resin replacement during restarts.

It goes without saying that a water softener in perfect operating condition before you go on vacation has a higher chance of functioning properly after a long slumber. Do not expect a damaged water softener to work like a brand-new unit when you return from a holiday break.

Lastly, did you fail to protect the water softener from temperature extremes and harsh chemicals while you were gone? These environmental and chemical factors can damage the resin beads, leaving you with a non-functioning water softener when you return from a vacation.


Getting the best marine water softener is very much possible, but it takes some time and a little effort from your part. Overall, you’d have to identify your needs, including your budget, so you can have a proper direction in choosing the top-rated unit to bring home. We’re hoping that this buying guide will help you determine the right water softener that works for your requirements. Know the things to check so that you can decide better. Take some time to compare those presented earlier to figure out the essential features you want for your water softener to have. Buy your marine water softener today!

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