
SX19
18′ 11″ · jet current
13′ 4″ of open water
Master Spas · H2X Trainer Series

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The maker doesn't publish the open water on the Trainer 19D MAX. Seats, steps and the current housing take their share of the 19′ 3″, so ask the dealer for it.
4 air-injected swim jets on 2 pumps
Air is mixed into the stream: it feels strong on your palm but gives you less water to pull against. The same pumps also feed the seats, so current and massage share the power.
How currents compare →Lap swimmers like 78 to 82°F and a hot tub runs 100 to 104, so you pick a compromise or change the setting and wait.
Is dual temperature worth it →No California listing we could match
California lists what a spa draws on standby, with the cover on. We found no listing that matches this model. Seven Master Spas swim spas have one, from 241 to 404 W.
We haven’t found enough owner reports on Master Spas swim spas to call a pattern yet. Ask the dealer for two owners near you that you can call.
These findings cover the Master Spas swim spa line; each names the models it applies to.
Doesn’t have: circulation pump, cooling, cover lifter.
Ten things that decide whether a swim spa works for you and lasts, answered for Master Spas’s swim spas. Tap any for the detail.
Master Spas builds four kinds of current. The Michael Phelps models push water with a belt-driven propeller set in 100 steps; Challengers use six airless jets fed by three pumps, Trainers four air-injected jets from two pumps, and Therapools a two-speed stream that Master Spas says may not be ideal for stationary swimming. On the Trainers, Challengers and the Therapool SE and D the swim pumps also feed seats or the therapy cove through diverters (on the Therapool 13 and 15 one pump runs only the swim end), and no flow, width or horsepower is published for any current.
What this means, and how to check it →masterspascdn.com ↗masterspascdn.com ↗
Master Spas publishes only outside cabinet sizes, 11 to 21 feet long and 51 or 60 inches tall (48 on the Therapool 13), plus 'around 51 inches' of water depth for the MP series. It calls the two 19D MAX models the largest H2X swim areas but prints no open-lane length or width for any model, and the 21-foot dual-zone models give part of their length to a sun deck and a hot tub.
What this means, and how to check it →masterspascdn.com ↗michaelphelpsswimspa.com ↗
Master Spas lists a coated wood frame with fiberglass-reinforced billets at the top flange, full-foam insulation and, on the Michael Phelps models, a high-density polymer base. It publishes no shell laminate, frame gauge or design for any swim spa, and its structure warranty (10 years, 7 on Therapool) covers water loss, with removal and replacement of a failed unit at the owner's cost.
What this means, and how to check it →h2xswimspa.com ↗michaelphelpsswimspa.com ↗
The 2026 manuals ask for a concrete pad at least 4 inches thick with crossed rebar on a firm, level surface, warn that a crane may be needed, and list full weights up to 24,775 pounds, advising 15% extra when planning delivery. Most H2X models need one 50-amp GFCI circuit, the 21-foot H2X models two, the MP Signature Pro one 60-amp, and the MP Momentum D three circuits totaling 130 amps; Challengers also need specific GFCI breaker brands.
What this means, and how to check it →masterspascdn.com ↗masterspascdn.com ↗
Master Spas insulates every H2X and MP swim spa with full foam. Nine exercise-spa listings in California's database carry current model numbers, at 241 to 483 standby watts, or 47% to 82% of each size's limit. The two for the 15D models list about 1,900 gallons against the 1,595 Master Spas now publishes, so our model pages use only the other seven. The Momentum D's hot tub side uses 191 of its 197 allowed watts, and we found no matching listing for the 19- and 21-foot H2X models.
What this means, and how to check it →h2xswimspa.com ↗michaelphelpsswimspa.com ↗
Each splits the cabinet into two bodies of water with independent temperature controls and separate control systems. The 21-foot H2X models put 370 gallons on the hot side and need a second 50-amp circuit; the Momentum D uses a clear acrylic divider, a 275-gallon hot side and three circuits totaling 130 amps. Master Spas publishes no figure for heat crossing the divider.
What this means, and how to check it →h2xswimspa.com ↗michaelphelpsswimspa.com ↗
The manuals name the main equipment panel for each model, say every side must stay reachable, and fit slice valves and unions so pumps and the heater can be serviced without draining. The warranty doesn't pay for access and lets dealers charge travel and access fees; full foam makes plumbing leaks slower to reach, and the MP propeller's critical parts must be identical factory components.
What this means, and how to check it →masterspascdn.com ↗masterspascdn.com ↗
The 2026 cards pay parts and labor on structure, surface, equipment and plumbing repairs, while jets and skirting are parts only. Structure means water loss, and if a spa is replaced the owner pays removal, reinstallation, access and any deck or fence damage; covers and freeze damage are excluded, the MP propeller has only 2 years, and the Therapool product pages still show the longer Trainer terms.
What this means, and how to check it →masterspascdn.com ↗masterspascdn.com ↗
Every model ships with the Deluxe Quad-Fold Cover, which Master Spas says meets ASTM F1346 for lockable safety covers; the MP site lists 5- to 3-inch tapered foam. Manual and hydraulic lifts are extra, the Axis roll-up cover is an option with a 3-year parts-only warranty, and the 21-foot H2X models can take a hybrid Axis-and-foam cover.
What this means, and how to check it →h2xswimspa.com ↗michaelphelpsswimspa.com ↗
Claims go in writing to the selling dealer within 10 days. If the dealer won't act, the owner contacts Master Spas. The dealer or an approved independent service center inspects the spa, and dealers may charge for travel. Controls are mainstream Gecko and TP500 systems, while the MP propeller's critical parts come only from the factory.
What this means, and how to check it →h2xswimspa.com ↗michaelphelpsswimspa.com ↗
What Master Spas leads with, where it covers the Trainer 19D MAX, and what the documents show.
What they sayMaster Spas calls itself the world's largest swim spa manufacturer and builds every swim spa on its Fort Wayne, Indiana campus, with U.S. and imported components.
What the documents showThe Fort Wayne campus is real and gained a dedicated swim spa building in its 2018 expansion, but Master Spas publishes no production figures behind 'largest', and part of every spa is imported.
Who else does itOther swim spa makers also build in North America, PDC in Pennsylvania and Hydropool in Ontario among them; the 'largest' title is self-awarded.
What they sayMaster Spas calls the Trainer 15D the world's best-selling swim spa: four air-injected VIP jets on two pumps, therapy seats and a standing therapy cove.
What the documents showNo sales figures back 'world's best-selling'. Master Spas itself puts the Trainer's top pace at 1:50 per 100 meters, against 1:20 for its Challenger.
Who else does itAir-injected multi-jet swim spas are the most common kind; the Velocity Injector Plate around the jets is Master Spas' own design.
Applies to: H2X Trainer 12, 15, 15D, 19D MAX, 21, 21D
What they sayEvery current model page lists EcoPur Charge, a copper and zinc filter core, plus ozone as standard in North America, sold as cleaner water with fewer chemicals; the Signature Pro adds the Mast3rPur UV and ozone system as standard, and the Temp+Control versions of the 15D models swap EcoPur for Mast3rPur.
What the documents showIt is standard and real, but Master Spas gives no chemical-reduction figure, and you still add sanitizer.
Who else does itMost rival mineral systems are silver cartridges; Master Spas' patents cover a copper-zinc filter assembly.
Years of cover as Master Spas publishes them. Who pays labor, travel and removal matters as much as the years, so read the card before you sign.
Parts and labor on structure, surface, equipment and plumbing repairs; jet internals 5 years parts only (owner pays shipping and fitting); skirting lifetime parts only; Temp+Control heat pump 2 years parts and on-site labor where fitted; ozonator, LED and UV 1 year; audio 1 year parts, 90 days labor. If the spa is replaced, removal and replacement labor and equipment are the owner's cost, as are any removal from the premises, damage to landscaping, decking or fencing, and the cost of getting access. Dealers or approved service centers may charge reasonable travel, and access charges apply if the spa isn't reasonably accessible. Claims go in writing to the selling dealer within 10 days (MasterSpas customer service if the dealer won't act); a non-covered call is billed to the owner. Covers, exercise kit and the unwired factory-supplied GFCI (H2X Challenger) are excluded, as are freeze damage, uneven support, operation outside 34-104 F, clogged or unapproved filters, and sun damage under a non-insulating or unapproved cover. Commercial use voids it; at a residential rental, terms of 4+ years drop to 2 and 2-3 years drop to 1. First owner only; void on sale or if the spa is moved.

18′ 11″ · jet current
13′ 4″ of open water

19′ 8″ · jet current

18′ 4″ · jet current
11′ of open water

18′ 4″ · jet current
12′ 4″ of open water
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