Support Center / Therapies & Operation / The Aromatherapy Canister: How It Works, What Goes In It, How It Is Plumbed and Which Tubs Can Have It
Back to Therapies & Operation

The Aromatherapy Canister: How It Works, What Goes In It, How It Is Plumbed and Which Tubs Can Have It

Updated September 2026

▶Glossary6
  1. What the Canister Is
  2. How to Use It
  3. Why the Scent Goes in the Canister and Not in the Jets
  4. Which Tubs Can Have It
  5. Related Guides
  6. Common Questions

The aromatherapy option on an Ella's Bubbles walk-in tub is a small canister plumbed into the jet system, with a chrome twist cap sitting flush on the tub deck. You twist the cap open, add a scent cartridge or your chosen bath scent or essential oil, twist it closed, and the water circulating through the jets picks up the aroma and carries it into the bath. It is a NuWhirl system, it is an option rather than a standard feature, and it can be installed on almost any Ella walk-in tub that has enough free deck space.

Essential oil bottles, bath salts, soap and a candle arranged beside a bathtub for aromatherapy
Essential oils are the recommended scent for the aromatherapy canister; keep salts and bombs out of the jets.

What the Canister Is

Ella's Bubbles partners with NuWhirl for this system. NuWhirl's aromatherapy canister is a four-part plumbing assembly that lets bathers easily insert and replace personalized bath scents or essential oils. The four parts are:

  • Easy Grip cap. The filler cap is designed to be gripped and twisted open easily whenever you need to reach the scent cartridge. It is available in a chrome finish only, and it is the only part you see or touch as a bather.
  • Specialized canister. The canister body is shaped to maximize the aroma dispersed into the bath and accommodates the most commonly available scent cartridges. It measures 1 5/8 inches in diameter and 2 7/8 inches long, with a 1 inch pipe spigot fitting on the bottom.
  • Nut. A 0.6 inch thick nut with 1 15/16 inch wrench flats secures the canister through the deck from below.
  • Tee. The canister sits on a standard 1 inch Schedule 40 PVC tee. NuWhirl calls this "standard tee installation" because it gives the installer flexibility to plumb the canister into either a pressure line or a vacuum line of the jetting system.

The cap itself is 2 3/8 inches in diameter and 1 1/8 inches tall. The deck hole is cut with a 1 11/16 inch hole saw. Everything except the cap lives beneath the deck, so if you have been looking for a separate diffuser or tray, there is none; the chrome cap is the whole visible system.

How to Use It

  1. Twist the chrome cap open.
  2. Insert a scent cartridge made for whirlpool aromatherapy canisters, or add your chosen bath scent or essential oil.
  3. Twist the cap closed.
  4. Fill the tub past the jets and run the hydro massage as usual. The circulating water passes the canister and disperses the scent through the jets.
  5. Replace or refresh the scent whenever you like by opening the cap again.
Aromatherapy Installation Explained

This installation video has no narration; it is a visual walkthrough of the canister assembly. It shows the four parts described above going together: the tee in the plumbing line, the canister dropping through the deck hole, the nut tightening from below, and the chrome twist cap finishing the top. Watching it with the dimensions above makes clear why the bather only ever handles the cap, and why the option needs both free deck space and access to the plumbing behind the apron. Watch: Ellas Bubbles: Aromatherapy Installation Explained on its own page.

Why the Scent Goes in the Canister and Not in the Jets

Ella's cleaning guidance allows oils, fragrances and salts in the bath but discourages them, because they leave residue in the pump and jet lines and call for more frequent vinegar flushes. Bath bombs are to be avoided altogether, since their ingredients can damage the pump system. The canister was designed to solve this: a cartridge or a small amount of scent held in one chamber gives you the aroma without pouring oil through the whole system. Our article on Epsom salts, bath bombs and oils covers the full additive rules, and the monthly maintenance guide explains the vinegar flush.

Which Tubs Can Have It

Ella's FAQ states that the aromatherapy option can be installed on almost any walk-in tub if there is sufficient deck space, particularly when it is combined with other options that also take up deck space. The cleanest way to get it is to include it in your order so the deck hole and tee are done at the factory. For a tub that is already installed, adding it means cutting a 1 11/16 inch hole in the deck and teeing into the jet plumbing behind the apron, which is a job for a licensed contractor; ask the team first so they can confirm your model has the space and the right line to tap. Aromatherapy is listed among the factory-built systems in what can and cannot be customized, alongside the LED chromatherapy light covered in the chromatherapy guide. For help weighing it against the other options, see common questions about choosing therapies.

Common Questions

How does the aromatherapy option work and where does the scent go?
To use the aromatherapy option, twist the chrome twist cap open, add a scent cartridge or your chosen bath scent or essential oil, then twist the cap closed. Fill the tub past the jets and run the hydro massage as usual; the circulating water passes the specialized canister and disperses the aroma through the jets into the bath.
Which tubs can have aromatherapy added?
The aromatherapy option can be installed on almost any Ella walk-in tub that has enough free deck space. It is a NuWhirl system and an option, not a standard feature on any model, so include it in your order. You can confirm your specific model's compatibility with your Ella dealer or the Ella's Bubbles team.
Can I put essential oils in the jets instead?
Ella's Bubbles cleaning guidance allows oils, fragrances, and salts in the bath water but discourages them because they leave residue in the pump and jet lines, requiring more frequent vinegar flushes. The aromatherapy canister was designed to solve this by holding the scent in one chamber, preventing oil from circulating through the entire jet system. Bath bombs should be avoided altogether, as their ingredients can damage the pump system.
What does the canister look like and where is it mounted?
From above the tub deck, only the chrome twist cap of the NuWhirl aromatherapy system is visible. The specialized canister, a 0.6 inch thick nut, and a standard 1 inch Schedule 40 PVC tee are mounted below the deck in the jet plumbing. The canister body measures 1 5/8 inches in diameter and 2 7/8 inches long, with a 1 inch pipe spigot fitting on the bottom, while the cap is 2 3/8 inches in diameter and 1 1/8 inches tall.
I cannot find a diffuser tray. Is something missing?
No, there is no separate diffuser tray for the Ella's Bubbles aromatherapy system. The chrome twist cap that sits flush on the tub deck is the only visible part of the system. Everything else, including the specialized canister, nut, and 1 inch PVC tee, is plumbed beneath the deck.
I added scent and smell nothing. What should I check?
First confirm the canister was on your order, since it is an add-on and a tub without one has nowhere to hold the scent. Then check that the scent is inside the canister rather than in the water or a loose tray, that the canister is not empty, and that the tub is filled past the jets with the hydro massage running. If you have a loose part marked aroma and cannot place it, send a photo of it and of the tub's accessible plumbing with your order details through ellasbubbles.com/support.
Can it be added after installation?
Possibly. It means cutting the deck and teeing into the jet plumbing behind the apron, a job for a licensed contractor. Open a ticket at ellasbubbles.com/support with your model and serial number so the team can confirm the space and the right line to tap.
What scents can I use, and can I buy cartridges from Ella?
Essential oils are the recommended scent, and the canister is shaped to accommodate the most commonly available scent cartridges made for whirlpool aromatherapy canisters. Ella does not list scent cartridges as an accessory. If you are unsure whether a particular product is suitable, ask the team before using it.
Can I put bath crystals or beads in the aromatherapy canister?
No, you should not put bath crystals or beads in the aromatherapy canister. Use only a liquid essential oil or a scent cartridge made for whirlpool aromatherapy canisters, as undissolved crystals or beads can block the canister. Additionally, keep salts and bath bombs out of the jet system entirely to prevent residue buildup and potential damage.
Does the Ultimate include aromatherapy?
The Ultimate includes the LED chromatherapy light as standard. Aromatherapy is an add-on option on most tubs rather than a standard feature, so include it in your order if you want it. Your Ella dealer or the team at (800) 480-6850 can confirm what your configuration includes.
Is there a simpler option?
Yes. Adding a few drops of diluted aroma oil to the bath water also works; keep oils diluted so the acrylic is not discolored, and plan on the monthly vinegar flush, since oils leave residue in the pump and jet lines. The canister remains the intended place for scent if you use it regularly.

For anything model-specific, open a ticket at ellasbubbles.com/support or call (800) 480-6850 and the team will be glad to help.

About this guide. Answers in the Ella’s Bubbles Support Center are compiled from real conversations with tub owners, our technicians’ notes and the product documentation, then reviewed by our team. Tub models and options have evolved over the years, so a detail here may differ slightly from your exact tub. If something looks different on yours, send us your serial number and a specialist will confirm it for your model.

Related guides

Did this solve your question?

If not, open a ticket and our team will pick it up from here.

Open a Support Ticket