How to Stay Safe from Legionella in Your Hot Tub

Legionella bacteria might sound like something out of a science class, but it’s a real concern for hot tub owners. If not properly maintained, your spa could become a breeding ground for this harmful bacteria.

This guide is based on expert advice from the CDC (Centers for Disease Control and Prevention).

What Is Legionella?

How to Stay Safe from Legionella in Your Hot Tub

Legionella is a bacteria that grows in warm water. Inhaling mist containing it can cause Legionnaires’ disease (a serious pneumonia) or a milder illness called Pontiac fever.

Hot tubs that aren’t properly maintained are one of the most common places Legionella can grow.

Who’s Most at Risk?

  • People aged 50 or older
  • Current or former smokers
  • Anyone with lung disease or weakened immunity

The good news is that Legionella can be prevented!

How to Prevent Legionella in Your Hot Tub

Prevention comes down to good hot tub water care and regular maintenance. Follow these steps:

1. Maintain proper disinfection levels

  • Free chlorine: ≥ 3 ppm
  • Bromine: ≥ 4 ppm
  • pH: 7.0 – 7.8

2. Clean the tub regularly

Scrub all surfaces, wash filters, and clear jets of biofilm or slime.

3. Change the water when needed

Replace spa water every 1–3 months (depending on use) and follow manufacturer guidance on filter replacement.

4. Be cautious with public hot tubs

  • Ask how often the water is tested
  • Check cleaning and disinfection routines
  • Confirm filters and jets are maintained

Know the Symptoms

If you’ve recently used a hot tub and develop a cough, fever, or shortness of breath — seek medical advice and mention your hot tub use.

For more details, see the official CDC guidance:

Preventing Legionella from Hot Tubs – CDC.gov

Hot tubs are designed for relaxation — but they require responsible care. With the right maintenance, your spa will stay safe, clean, and worry-free.