Best Portable Water Softeners for RVs and Campers
Quick answer: For most RVers, a 16,000-grain unit such as the On The Go Double Standard or the Pro+Aqua WS-P-16 is the best balance of size and time between regenerations. If space and weight matter more, a 10,000-grain unit like the Watts RV-Pro 10,000 or Camco TastePURE is smaller and uses less salt per regeneration, but you will regenerate more often. All four are real ion exchange softeners that you recharge by hand with ordinary table salt.
How Portable Softeners Work
A portable water softener is a small version of a home softener: a tank of ion exchange resin with a head that takes a garden hose in and out. As hard water passes through, the resin holds on to calcium and magnesium and releases sodium in their place. When the resin is full, you flush it with strong salt water (brine), which pushes the hardness minerals off and recharges the resin. That flush is called regeneration.
The difference from a home system is that there is no control valve, no brine tank and no electricity. You decide when to regenerate, usually when a test strip shows hardness coming through, and you do it by hand with table salt and a hose. That makes these units cheap, simple and easy to carry, which is why they are popular for RVs, travel trailers, boats and campground hookups where hard water can quickly leave scale in water heaters, faucets and shower heads.
Capacity is listed in grains: the total hardness the resin can remove before it needs regenerating. Divide that number by your water's hardness in grains per gallon (gpg) and you get roughly how many gallons of soft water you will get per regeneration. Real results are usually somewhat lower, because no softener uses all of its capacity perfectly.
Comparison Table
| Unit | Capacity | Salt per Regeneration | Size | Weight | Source |
|---|---|---|---|---|---|
| On The Go Double Standard | 16,000 grains | 2 boxes of table salt | 22 in H x 9.5 in dia. | 34.18 lb listed | Retail listing |
| Pro+Aqua WS-P-16 | 16,000 grains | About 4 lb (or about 2 lb with the optional regeneration kit) | Not stated in manual | Not stated in manual | Owner's manual |
| Watts RV-Pro 10,000 | 10,000 grains (0.33 cu ft resin) | 2 lb | 21 in H x 9 in W | 26 lb | Installation sheet |
| Camco TastePURE (40655) | 10,000 grains | 2 boxes of table salt | 20.5 in H x 8.5 in dia. | 22.70 lb listed | Retail listing |
Listed weights from retailers may be shipping weights. Camco lists flow "up to 4 GPM"; we did not find official flow ratings for the other three. Specifications can change between production runs, so check the listing before you buy.
The Four Units in Detail
1. On The Go Double Standard (16,000 grains): Best for Full-Time RVers
On The Go's Double Standard is the best-known RV softener, and its 16,000-grain rating is double the company's standard model. The retail listing says it gives up to 1,600 gallons of soft water per regeneration, regenerates with two boxes of common table salt in under 30 minutes, and comes with a back-flush adapter, a 4-foot drinking water hose and hardness test strips. Note that 1,600 gallons assumes water of about 10 gpg; harder water means fewer gallons. One listing notes that later versions no longer include a shutoff valve, so check what is in the box. It is the largest and heaviest unit here, so plan where it will ride.
2. Pro+Aqua WS-P-16 (16,000 grains): Best Instructions and Optional Regeneration Kit
The Pro+Aqua Travel Series matches On The Go's 16,000-grain capacity and has the clearest owner's manual we found. It ships with new resin, needs a 5-minute pre-flush before first use, and can be regenerated two ways: by pouring about 4 lb of table salt into the tank and letting it soak for 40 to 50 minutes, or with the optional WS-P-REG-KIT housing, which uses about 2 lb of salt and doubles as a prefilter afterward. Pro+Aqua sells replacement resin (part MED-CAT-025/2) and gives a one-year limited warranty. The manual says the unit must run upright but can travel on its side if well sealed.
3. Watts RV-Pro 10,000: Best Compact Pick
Watts' RV-Pro uses 0.33 cubic feet of high-capacity resin in an 8 x 18 inch tank and needs just 2 lb of salt per regeneration, with a 20-minute brine rinse. Its standout feature is a Y valve with a built-in drain flow restrictor. Watts says it found that guessing at the drain flow rate during the brine rinse could change system capacity by as much as 50%, so the restrictor sets it for you. It includes 50 test strips and tells you to regenerate when hardness passes 3 gpg. Warranty is 5 years on the tank and 1 year on the head.
4. Camco TastePURE (10,000 grains): Lightest Option
Camco's TastePURE is the smallest unit here at 8.5 by 20.5 inches. The listing gives a 10,000-grain capacity, flow up to 4 GPM, and regeneration with two boxes of common table salt through a wide fill opening. The kit includes 50 test strips, a 4-foot hose and the male-to-male hose fitting you need to regenerate. It is a good fit for weekend campers and smaller trailers with lighter water use.
How Many Gallons You Will Get
Pro+Aqua's manual gives the simple rule: divide the grain capacity by your water hardness to get gallons between regenerations. Here is what that looks like at common hardness levels (rated capacity; expect real-world results to be a bit lower):
| Water Hardness | 10,000-grain unit | 16,000-grain unit |
|---|---|---|
| 5 gpg (85 ppm) | about 2,000 gal | about 3,200 gal |
| 10 gpg (171 ppm) | about 1,000 gal | about 1,600 gal |
| 15 gpg (257 ppm) | about 670 gal | about 1,070 gal |
| 20 gpg (342 ppm) | about 500 gal | about 800 gal |
| 25 gpg (428 ppm) | about 400 gal | about 640 gal |
To convert a campground or city report given in mg/L or ppm to grains per gallon, divide by 17.1. Because RV parks change from stop to stop, the most reliable way to know when to regenerate is to dip a hardness test strip in the softened water every week or so. When it reads around 3 gpg or more (Watts' guideline), it is time. Our test kit guide covers the best strips and kits.
How to Regenerate
Each brand has its own steps, so follow the manual that came with your unit. The general pattern from the Watts and Pro+Aqua instructions is:
- Shut off the water and relieve the pressure. Watts opens the drain port on its Y valve to do this.
- Drain some water out of the tank by tilting it, so there is room for salt.
- Add the salt through the fill port or opening: 2 lb for the Watts, about 4 lb for the Pro+Aqua without its kit, two boxes for On The Go and Camco. Use plain table salt (sodium chloride).
- Let it soak. Watts waits 5 minutes; Pro+Aqua's no-kit method soaks 40 to 50 minutes, shaking every 10 minutes.
- Slowly rinse the brine through. Watts runs a 20-minute brine rinse through its restrictor. Pro+Aqua runs a pencil-size stream for 10 to 15 minutes, then full flow for 1 to 2 minutes.
- Rinse until no salty water comes out, then reconnect to the RV.
Where to drain: the rinse water is very salty. Pro+Aqua warns not to drain it on grass, flowers or trees. Use a campground drain or sewer connection where allowed, and follow park rules.
Watts also recommends a back flush twice a year: run water backward from the outlet to the inlet at about 1 gallon per minute to loosen and clean the resin bed, and do it before regenerating if you do both at once.
Storage, Sanitizing and Winter
- Regenerate before storing. Pro+Aqua's manual says always regenerate before storage, drain some water, and keep the unit in a cool place out of the sun.
- Sanitize after long idle periods. Watts says to back flush and then run the regeneration steps with about 1/4 cup of bleach (or its Sani-System solution) instead of salt, and then regenerate with salt before use. Pro+Aqua warns that chlorine breaks down resin, so do not sanitize more than needed.
- Never let it freeze or dry out. Both can damage the resin. Bring the unit inside or drain and store it before freezing nights.
- Do not open the tank head unless the manual says to. Watts warns that removing the head can spill resin and lower capacity.
- Secure it for travel. A full unit is heavy. Strap it down so it cannot tip or roll.
A Note on Certification
We checked NSF's NSF/ANSI 44 softener listing and did not find On The Go, Pro+Aqua, Watts RV-Pro or Camco portable softeners in it (NSF listing). That does not mean they do not work; it means their capacity and efficiency have not been independently verified to that standard. The capacities on this page are manufacturer and retailer figures. The easy check is the same for any softener: test the water coming out with strips. If it reads near zero, it is working.
Apartments and Renters
Many people search for a portable softener because they rent and cannot install a whole-house system. RV softeners connect with garden hose fittings, so they are not designed for indoor plumbing, and the salty rinse water needs a suitable drain. For renters, the practical options are usually:
- Ask the landlord. Some will allow a softener with a bypass valve that can be removed when you move. See our best water softeners guide and softener cost guide.
- Filter drinking water. A filter pitcher or reverse osmosis system improves taste; note that most pitchers do not soften.
- Protect hair and skin. Shower filters mainly reduce chlorine and do not soften water, but some people still find them helpful; see do shower filters work?
- Clean scale regularly. Our cleaning guides cover vinegar and citric acid methods for faucets, glass and appliances.
How to Choose
- Test the hardness where you camp most often.
- Estimate your water use. Full-timers and families use far more than weekend campers. Check your fresh tank fill-ups or a hose flow meter.
- Pick a capacity: 16,000 grains if you use a lot of water or camp in hard water areas; 10,000 grains if storage space, weight or salt use matter more.
- Check the box contents: hoses, adapters, test strips and any regeneration fitting.
- Read the warranty and check that replacement resin is available.
Hard water in your RV water heater? See our guide to softener troubleshooting if soft water stops coming through, and all water softener guides for home systems.
Frequently Asked Questions
Yes. Portable RV softeners use the same ion exchange resin as home softeners. They swap calcium and magnesium for sodium until the resin is full, and then you regenerate them with table salt. Test the outlet water with strips to confirm.
Divide the grain capacity by your hardness in grains per gallon. A 16,000-grain unit gives about 1,600 gallons at 10 gpg and about 800 gallons at 20 gpg; a 10,000-grain unit gives about 1,000 and 500 gallons. Real results are usually a little lower.
Plain table salt (sodium chloride). Watts uses 2 lb per regeneration, Pro+Aqua about 4 lb without its regeneration kit, and On The Go and Camco say two boxes of common table salt.
When a test strip shows hardness coming through. Watts recommends regenerating when hardness exceeds 3 grains per gallon.
They are built with garden hose fittings for RVs and need a place to drain salty rinse water, so they are not designed for indoor plumbing. Renters usually do better asking the landlord about a removable softener or filtering drinking water.
We did not find On The Go, Pro+Aqua, Watts RV-Pro or Camco portable softeners in the NSF/ANSI 44 listing, so their capacities are manufacturer and retailer figures.
Yes, and freezing or drying out can damage the resin. Drain it and store it indoors in freezing weather, and regenerate before storage.
Last updated: October 2026. Sources: Watts RV-Pro 10,000 installation sheet, Pro+Aqua WS-P-16 owner's manual, On The Go listing (Camping World), Camco listing (Camping World), NSF/ANSI 44 listing.