Why Ultrasonic Cleaners Must Be Used With Liquid
One of the most misunderstood things about ultrasonic cleaners is this:
“Can I just switch it on without water?”
“Why does it need liquid at all?”
“Does the solution actually matter?”
If you’re a professional nail technician using an ultrasonic cleaner for e-file bits and metal tools this is important.
An ultrasonic cleaner cannot function properly without liquid.
And here’s why.
Ultrasonic cleaners work using a process called cavitation.

Inside the machine:
- A transducer creates high-frequency sound waves
- These sound waves travel through liquid
- The waves create microscopic bubbles
- The bubbles rapidly form and collapse
- That collapse releases energy
- The energy dislodges debris from surfaces

The key detail:
Sound waves must travel through liquid.
No liquid = no cavitation.
No cavitation = no cleaning.
Why It Cannot Run Dry
Ultrasonic cleaners are not “vibration boxes.”
They rely on liquid as a transmission medium.
If you run an ultrasonic cleaner without liquid:
- Sound waves have nothing to travel through
- Energy reflects back into the transducer
- Internal components can overheat
- The tank can become damaged
- The unit lifespan shortens
Running dry can permanently damage the machine.
Most manufacturers specifically warn:
Never operate without liquid in the tank.
Why Water Is Essential
Water acts as the carrier for ultrasonic energy.
It allows:
- Even distribution of sound waves
- Proper bubble formation
- Consistent cavitation
- Safe energy transfer
For nail techs cleaning:
- Carbide e-file bits
- Diamond efile bits
- Cuticle scissors
- Metal pushers
Water allows cavitation to reach deep grooves and fine crevices.
Without liquid, none of that microscopic cleaning action happens.
Why the Type of Liquid Matters
Not all liquids are suitable.
Ultrasonic cleaning works best with:
✔ Water
Using the wrong liquid can:
- Reduce cavitation efficiency
- Damage tool coatings
- Create vapour hazards
- Corrode the tank
The liquid supports the cleaning process but it does not replace it.
Why Air Cannot Replace Liquid
Air molecules are too far apart to allow proper energy transfer.
Liquid molecules are close together, which allows:
- Compression waves
- Bubble formation
- Controlled collapse
This is basic physics.
Ultrasonic cleaners are designed to work in liquid because cavitation cannot occur in air.
What Happens If You Underfill the Tank?
If the tank is not filled to the correct level:
- Cavitation becomes uneven
- Cleaning becomes inconsistent
- Transducer strain increases
- Machine lifespan decreases
Always fill to the manufacturer’s recommended level.
Professional nail tech hygiene isn’t just about tools - it’s about maintaining your equipment too.
The Professional Nail Tech Standard
When using an ultrasonic cleaner:
1️⃣ Fill with water (or approved solution)
2️⃣ Place tools in the basket (not directly on tank base)
3️⃣ Run for recommended cycle
4️⃣ Rinse and move to disinfection
Remember:
Ultrasonic cleaning removes debris.
Disinfection kills microorganisms.
They are separate steps.
Ultrasonic cleaners require liquid because:
- Sound waves must travel through liquid
- Cavitation only occurs in liquid
- Running dry damages the machine
- Water enables microscopic debris removal
No liquid = no cavitation = no cleaning.
If you’re positioning yourself as a professional nail technician, understanding the science behind your equipment matters.
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