6 Person Four-Pump Hot Tub

When Daily Demands Require Real Recovery

Some days leave their mark. The King Ultra is built for people whose bodies need more than a quick soak—athletes recovering from training, professionals on their feet all day, anyone whose physical work catches up by evening. Up to 60 jets and air injectors target tension across extra-deep, extra-wide seating designed to accommodate how real bodies actually sit and stretch.

The King Ultra is Royal Spa’s flagship model—available exclusively in the Medical configuration with four pumps delivering maximum pressure to every position. Seating for 6 means room for others, but the engineering focuses on you: strategic jet placement developed with medical input puts hydrotherapy where your body needs it. At 94″ x 94″ with 575 gallons of water capacity, it’s substantial without overwhelming a typical backyard.

Engineering That Proves Itself

Royal Spa remains the only manufacturer with hot tubs engineered to safely accommodate Epsom salt—a capability competitors prohibit because it damages their equipment. That materials innovation extends throughout: Bio-Lok® antimicrobial protection, ozone purification, and the Smart Energy Hybrid Pump that keeps operating costs reasonable despite the four-pump power. Standard components mean any qualified technician can service it, avoiding the weeks-long waits common with proprietary systems.

Built in Indianapolis since 1981 with a 40-year structural warranty that proves engineering confidence. The King Ultra comes fully loaded: Medical Package upgrade, underwater lighting, deluxe step, chemical starter kit, and thermal cover—all standard. Customize shell colors, cabinet finishes, waterfall, LED lighting, or stereo to match your space.

Royal Spa products promote relaxation and general wellness. Not intended to diagnose, treat, cure, or prevent any disease.

King Ultra FAQs

How big is the King Ultra?

The King Ultra seats 6, holds about 575 gallons of water and can be configured with up to 60 jets. Its cabinet measures about 94″ x 94″ x 38″ (W x L x H). See how it compares with other models in our hot tub model comparison.

What builds are available for the King Ultra, and what does it cost?

The King Ultra is offered in the Medical build with 4 pumps. Listed pricing is $18,995. For a full breakdown, read how much a hot tub costs.

Can I use Epsom salt in the King Ultra?

Yes. Royal Spa hot tubs are built to be Epsom salt compatible. Learn more about Epsom salt in a Royal Spa hot tub.

What warranty comes with the King Ultra?

40 years on the structure, 10 years on the surface and 3 years on parts.

Where is the King Ultra made?

It is built by Royal Spa in Indianapolis, Indiana, where the company has manufactured hot tubs since 1981.

How soon can I get a King Ultra delivered?

Delivery timing depends on the build you choose and the current schedule, so ask your showroom: Factory Showroom (Indianapolis), Avon or Pendleton Pike.