On The Go vs PRO+AQUA: Which 16,000-Grain Portable RV Water Softener Is Better?

The On The Go Double Standard (OTG4-DBLSOFT) and the PRO+AQUA WS-P-16 both carry a 16,000-grain nominal softening capacity, so neither unit holds an inherent capacity advantage. Your choice comes down to vertical storage bay clearance, lifting weight, and how you prefer to load salt during regeneration:

• Choose the PRO+AQUA WS-P-16 if your RV utility bay or pass-through compartment has low vertical headroom. At 19.5 inches tall, it requires 2.5 inches less vertical clearance than the On The Go. It also includes brass/plastic quick-connect hose adapters and offers a 1-year standard warranty that extends to 3 years with product registration.
• Choose the On The Go Double Standard if you want a slightly lighter listed tank weight (32 pounds versus 35 pounds) and a faster, simpler standard regeneration routine without buying extra accessories. Its wide-mouth top opening accepts two 26-ounce boxes of table salt and uses a 30-to-38-minute combined two-stage rinse, whereas PRO+AQUA’s standard direct-fill method requires a 40-to-50-minute salt soak with manual agitation every 5 to 10 minutes before rinsing (unless you buy PRO+AQUA’s optional external regeneration kit).

All specifications, capacities, and maintenance steps below are manufacturer-attributed figures rather than independent test measurements, comparing two prominent portable RV water softener models.

Quick Summary

• Models Compared: On The Go Double Standard (OTG4-DBLSOFT) vs. PRO+AQUA Portable RV Water Softener (WS-P-16).
• Rated Capacity: 16,000 grains for both models.
• Listed Dimensions: On The Go measures 22 in H x 9.5 in diameter; PRO+AQUA measures 19.5 in H x 10 in x 10 in (including an integrated stabilizing base).
• Listed Weight: 32 pounds for On The Go; 35 pounds for PRO+AQUA (neither manufacturer specifies whether listed weights represent dry shipping or wetted operating conditions).
• Published Service Flow: 3 GPM for On The Go; not specified in PRO+AQUA’s standard product documentation.
• Standard Regeneration Salt & Timing: On The Go uses two 26-ounce boxes of table salt (3.25 pounds total) with a 24-to-30-minute slow rinse and a 6-to-8-minute fast rinse. PRO+AQUA direct-fill uses 4 pounds of table salt with a 40-to-50-minute soak (agitating every 5 to 10 minutes), a 10-to-15-minute slow rinse, and a 1-to-2-minute fast rinse.
• Operating Position: Both units connect via standard 3/4-inch garden hose threads, require no electricity, and must stand upright during operation.

Scenario-Based Decision Matrix

Because both tanks hold the same 16,000-grain rating, match your primary RV constraint to the documented model differences below:

Size, Weight, and Physical Handling

The two most common physical bottlenecks for a 16,000-grain softener are compartment doorway height and lifting effort. (For campers evaluating the smaller 8,000-grain alternative, examine the detailed trade-offs of the On The Go series in our dedicated review.)

Practical Consequences for Bay Fit and Transport

• Headroom beyond tank height: Measure the vertical opening of your utility bay door as well as the interior ceiling height. Because water hoses attach at the top of both tanks, allow extra clearance above the 19.5-inch (PRO+AQUA) or 22-inch (On The Go) tank body so supply hoses and 90-degree elbows do not kink.
• Lifting and draining: Neither manufacturer specifies whether the 32-pound and 35-pound figures represent dry shipping weight or water-saturated operating weight. Filled tanks will weigh more when saturated with water, so drain water from either tank before lifting it into a storage bay or truck bed.

Regeneration Workflow: Top-Pour vs. Direct-Fill vs. External Kit

Both brands advertise regeneration in under 30 minutes on their marketing pages, but the actual hands-on steps for recharging the resin beads with table salt differ substantially between their user manuals.

What This Means for Maintenance Day

If you buy the base softener without extra accessories, the On The Go Double Standard requires far less active supervision. You pour two 26-ounce boxes of standard table salt into the wide-mouth top opening, run a pencil-sized slow rinse for 24 to 30 minutes, and finish with a full-stream rinse for 6 to 8 minutes.

With the PRO+AQUA WS-P-16 out of the box, the direct-fill manual instructs you to add 4 pounds of table salt, let the unit soak for 40 to 50 minutes while manually agitating the tank every 5 to 10 minutes, and then run a 10-to-15-minute pencil-sized rinse followed by a 1-to-2-minute full-flow rinse. PRO+AQUA’s “under 30 minutes” regeneration claim applies when you pair the softener with its separately sold WS-P-REG-KITV2 regeneration kit, which dissolves salt inside an external clear housing so brine flows into the resin bed without removing the main tank head. If you prefer PRO+AQUA’s shorter 19.5-inch tank height but want to avoid the 40-to-50-minute soak-and-shake routine, factor the cost of the optional regeneration kit into your budget.

Soft-Water Gallon Yield and Flow Rate

Although On The Go advertises “up to 1,600 gallons” (or up to 40 days) and PRO+AQUA advertises “up to 2,000 gallons,” both units hold the exact same 16,000-grain nominal softening capacity. (If you are still deciding whether 16,000 grains fits your travel routine, see our guide on calculating your required grain capacity.) The difference in advertised gallon yield is purely mathematical and comes from each brand assuming a different incoming water hardness in grains per gallon (GPG):

$$\text{Approximate Soft-Water Gallons}=\frac{\text{16,000 Grains}}{\text{Source Water Hardness (GPG)}}$$

Flow and Filtration Boundaries

• Service flow rate: On The Go publishes a 3 GPM flow specification, whereas PRO+AQUA’s reviewed manuals and product pages do not publish a GPM rating, nor does either brand publish a pressure-drop curve across the resin bed.
• Softening vs. filtration: Both units are ion-exchange water softeners designed to reduce hardness minerals (calcium and magnesium), not contaminant or microbial water filters. On The Go describes its media as “high grade premium resin,” while PRO+AQUA’s manual notes an expected resin lifespan of 1 to 3 years depending on water quality and usage.
• Upstream sediment and chlorine protection: PRO+AQUA’s manual explicitly recommends placing a carbon block (CTO) pre-filter upstream (such as the housing included in its WS-P-REG-KIT) to protect the resin bed from chlorine and sediment degradation. Using a pre-filter upstream of any portable RV softener helps preserve resin life.

Connectors, Storage Rules, and Warranty

Before storing the PRO+AQUA unit between trips, the manufacturer’s manual instructs owners to regenerate the resin bed and strictly prohibits letting the tank freeze. Check PRO+AQUA’s current registration deadlines and terms directly with the manufacturer after purchase to secure the 3-year extended warranty coverage.

Scope Limits: What Available Documentation Does Not Establish

To keep this comparison transparent, note the technical areas where public manufacturer documentation is silent:

• No PRO+AQUA flow rating or pressure-drop curves: Because PRO+AQUA does not publish a GPM flow rate in the reviewed materials, we cannot verify whether one unit restricts RV fixture pressure less than the other.
• No documented third-party NSF resin certification numbers: The reviewed product pages and manuals for both models do not list specific NSF/ANSI certification numbers for the tanks or resin beds.
• Unspecified weight condition: Neither brand states whether its listed weight (32 lbs vs. 35 lbs) reflects dry shipping condition or wetted resin.

Frequently Asked Questions