Walk In Tubs With Jets: Water Jets vs. Air Jets vs. Microbubble

By Zach Wennstedt, owner of Aging Safely Baths. Selling and installing accessible bathing since 2012. Updated September 2026. This article is educational; ask your physician before using hydrotherapy for a medical condition.

"Do I need jets?" is the second question on almost every call, right after price. The answer depends on who is bathing and why, because the three jet systems on a walk in tub do three different jobs. Water jets massage muscle and joints. Air jets stimulate circulation and relax. Microbubble therapy treats skin. Two of them cost about $2,000 each installed. This guide explains how each one works, what it is good for, what it is not, how much it adds, and how to choose without paying for a system that will run twice and then never again.

Water jets (hydrotherapy): how they work

A pump, typically 5 to 7 amps on a dedicated GFCI circuit, draws water from a suction fitting in the tub and pushes it back out through jets set into the shell. Each jet has a venturi that mixes in air, which is why the stream feels fizzy rather than like a hose. An intensity dial adjusts the air mix, and on better tubs the jets swivel so you can aim them.

• Jet counts and placement. Hydro Dimensions runs 6 jets standard: 2 back, 2 calf, 2 foot, with the V-Back option putting 6 on the back plus calf and foot, or 4 back and 2 hip. Ella runs 10 seat jets plus 6 foot jets on most models, up to 16 seat jets on the TransferXXL. Meditub varies by model.
• What it feels like. Focused pressure, like a shower massage head against the muscle. Adjustable from gentle to firm.
• Who it helps. Osteoarthritis and rheumatoid arthritis, neuropathy in the feet, chronic low-back pain, post-exercise soreness, restless legs. Warm water alone does much of the work; the jets add the mechanical massage.
• Water hygiene. Because water passes through the pump and plumbing, hydro tubs need an ozone sterilizer (standard on Ella) or a periodic flush cycle, and you should not use bath oils or bubble bath in them.
• Noise. A pump hum, noticeable but not loud; comparable to a dishwasher in the next room.

Air jets: how they work

A blower, 4.5 to 6.4 amps, pushes warmed air through a manifold to 16 to 20 small jets in the seat and floor of the tub. The air enters as thousands of bubbles rising past the body. Nothing but air touches the plumbing, so there is no water in the lines to sanitize; most blowers run an auto-purge cycle about 20 minutes after you shut off to dry the lines.

• What it feels like. A gentle, effervescent tingling over the whole body rather than pressure on one spot. Three speeds on most systems.
• Who it helps. Poor circulation, mild swelling in the legs and feet, stress and sleep, sensitive skin that cannot take firm pressure, people on blood thinners who bruise easily.
• Warmth. Air jets can cool the water slightly over a long soak; an inline heater fixes that on dual systems.
• Noise. The blower is the louder of the two motors. Fine in a bathroom with the door closed; ask about placement if the bedroom shares a wall.

Microbubble therapy (PureBubbles): how it works

This is the newest of the three and the one that surprises people. Hydro Dimensions calls its system PureBubbles; Ella calls it Microbubble. Both use a dedicated 1 HP pump and a pressure vessel to dissolve air into water under pressure, then release it through an agitator valve. The result is billions of bubbles about 10 microns across, small enough to pass into skin pores, which are roughly 50 microns. The water turns an opaque, silky white.

• What it does for skin. The bubbles carry extra oxygen, about 70 percent more than tap water, and as they collapse against the skin they lift oils, dead cells and odor-causing bacteria out of the pores. Manufacturers report cleaner, softer, better-hydrated skin after a 20 minute soak, with fewer breakouts and less itch for people with dry skin, eczema, psoriasis and similar conditions. It is non-invasive and needs no soap.
• What it does not do. It is not a massage. There is no pressure; the sensation is warmth and silkiness. It also does not replace prescribed treatment for a skin condition; think of it as a very good bath.
• Who chooses it. Bathers with dry, itchy or fragile skin, diabetics who need gentle skin care, and anyone who bathes to relax rather than to work a sore joint. It is common to pair it with air jets and skip water jets entirely.
• Cost. A factory option on Hydro Dimensions and Ella tubs; ask for the microbubble package price on your quote, it varies by model.

Side by side: which jets for which bather

Every jet decision is made at order time. Jets are plumbed into the shell at the factory, so you cannot add them later without replacing the tub.

Dual and triple systems: worth it?

A dual system (water plus air) runs each system independently, so the bather can use either or both. Ella's Royal and TransferXXL offer triple packages (air, hydro and microbubble) with LED chromatherapy included. Whether the extra $2,000 to $4,000 is worth it comes down to one question: is there more than one bather, or one bather with more than one need? A couple where one person has arthritis and the other has circulation problems is a clear dual. A single bather with dry skin is a microbubble-and-air, or microbubble alone. A single bather who wants to be safe in the tub is a soaker with a heated seat, and we will tell you that on the phone even though it is the lowest ticket.

Options that matter more than jets

• Heated seat and backrest. The single most-loved option. Keeps the bather warm during fill and drain, which is the time people complain about. Inexpensive.
• Fast-fill faucet. Up to 18 gallons per minute; cuts fill time in half. Needs three-quarter inch supplies.
• Inline heater. Keeps a long jetted soak at temperature; standard on many hydro packages.
• Dual drains. 80 seconds to 3 minutes to empty. Standard on Ella; ask on others.
• Chromatherapy. Underwater LED color lighting; included with dual packages on Ella, an option on Hydro Dimensions. Calming for dementia patients in particular.
• Aromatherapy. A diffuser in the air system; a small extra that some bathers love.
• Digital controller. One panel for all systems, easier for arthritic hands than several push buttons.

Electrical and plumbing requirements

Each motor needs its own dedicated GFCI-protected circuit, 110/120 volt, 15 or 20 amp, from the panel to a disconnect within reach of the tub. Our installed jet prices include the GFCI disconnect and up to 25 feet of run; longer runs are $15 per foot. Water heater: 40 gallons is fine for a compact soaker; a jetted or deep tub should have 50 gallons or a tankless unit, because a heater that runs out mid-fill is the number one reason people say their jetted tub "does not work." Supplies: half inch for a standard faucet, three-quarter inch for fast-fill. Drain: 2 inch. Everything is on the factory schematics on each product page.

Safety and medical notes

• Ask a physician before hydrotherapy if the bather has unstable blood pressure, congestive heart failure, open wounds, a pacemaker, or is pregnant.
• Keep water at or below 104°F; 100 to 102°F is comfortable for most seniors. An anti-scald valve is cheap insurance.
• Diabetics with neuropathy cannot always feel heat; test water with a thermometer, not a foot.
• Limit jetted soaks to about 20 minutes and hydrate before and after.
• No bath oils, salts or bubble bath in water-jet tubs; they foul the pump. Microbubble and air systems are fine with plain water only.
• Run the ozone or flush cycle as the manual says; a monthly pipe cleaner keeps hydro lines clear.

Models by therapy package

Or drag the jets where you want them on our Design Your Bathroom tool and print the spec sheet.

How the brands' jet systems compare

Three good systems. Hydro Dimensions is the pick for buyers who want USA-made and a lifetime shell with a labor warranty on self-installs. Ella is the pick for the deepest therapy menu, especially the triple package and the wheelchair transfer line. Meditub is the value pick with fewer options and simpler controls.

Anatomy of a jetted walk in tub

Behind the access panel on the apron, here is what an installer or a curious owner will find, front to back:

• Suction fitting with a safety cover, low in the tub, where the hydro pump draws water.
• Hydro pump on a rubber-isolated mount, wired to its own GFCI disconnect.
• Ozone generator (Ella) inline with the pump, sterilizing water on every cycle.
• Inline heater after the pump, maintaining temperature.
• Jet manifold, flexible PVC lines running to each jet body with a check valve.
• Air blower on the opposite side, with a check valve and a heater element, feeding a separate manifold to the air jets.
• Microbubble pump and pressure vessel when fitted, feeding a single agitator outlet.
• Dual drains with cable-operated levers to extended handles on the deck.
• Leveling feet on a stainless frame; four to six of them, adjusted to a dead-level rim.

All of it is serviceable through the front apron without touching the walls, which is the practical reason to leave the apron accessible rather than tiling over it.

The science behind warm-water therapy, briefly

Hydrotherapy is one of the oldest treatments in medicine and one of the few that has held up. Warm water at 100 to 102°F does four measurable things: it reduces the effective weight of the body by about 90 percent when submerged to the shoulders, unloading arthritic joints; it raises skin and muscle temperature, which increases blood flow and lowers muscle tone; it triggers the release of endorphins that dull pain signals; and the hydrostatic pressure of the water on the legs pushes pooled fluid back toward the core, which is why ankles look better after a soak. Jets add mechanical stimulation on top of that: water jets work like a massage therapist's thumbs, air jets like a light effleurage stroke. Microbubbles act on the skin surface rather than the tissue underneath.

What the evidence does not support is any claim that a jetted tub cures a condition. It relieves symptoms, sometimes dramatically, and it is a real quality-of-life improvement for people with arthritis, fibromyalgia, neuropathy and chronic pain. Treat the therapy package as a comfort and symptom-management decision, made with the bather's doctor, and you will not be disappointed.

Maintenance, year by year

• Weekly: wipe the shell, rinse the jets, leave the door open to dry the seal.
• Monthly: run a pipe-cleaning tablet through water-jet systems; check the auto-purge ran on air systems.
• Twice a year: inspect the door seal for nicks, tighten the drain lever, check the GFCI test button.
• Yearly: descale the fast-fill faucet aerator in hard-water areas; replace the ozone cell when the light indicates.
• Never: abrasive cleaners, bath oils in hydro tubs, or a pressure washer on the door seal.

Do that and a walk in tub with jets outlasts the bathroom around it. Shells carry lifetime warranties; pumps and blowers are typically covered 3 to 10 years and are replaceable through the access panel without disturbing the tub.

What jets cost, and what they do not

Water jets add $2,000 installed; air jets add $2,000; the V-Back upgrade is $700 more on top of water jets. Microbubble is quoted per model. Those prices include the dedicated GFCI disconnect and 25 feet of electrical run. They do not change fill time, drain time, installation time or warranty. National TV brands bundle a dual package into a $25,000 to $30,000 quote; the same jets on the same class of tub, installed by factory-certified crews, put most projects between $17,500 and $19,500 with us before promotions and the veteran discount. The itemization is on our cost page.

Bottom line

Jets are a medical decision dressed up as a luxury option. Match the system to the diagnosis: water for joints and nerves, air for circulation and calm, microbubble for skin. Buy the heated seat no matter what. And if there is no diagnosis, buy the soaker and spend the difference on the fast-fill faucet and a nice bath mat.