Extended Hot Tub/Spa Closures

Take steps to help keep Legionella and other bacteria from growing in hot tubs/spas

woman relaxing in an outdoor hot tub

Extended closures of hot tubs/spas could create conditions favorable to Legionella and other bacterial growth in the hot tub/spa if:

  • They are in a public aquatic facility that will be closed for weeks or months, and
  • A qualified operator is unable to maintain water quality during the closure.

Check for existing regulations and guidelines from your local or state regulatory agency before using these recommendations. They do not replace:

  • Existing regulations or guidelines from your local or state regulatory agency or
  • Consultation with a service company or the company or engineer that designed the aquatic facility.

How to Close a Hot Tub/Spa

What is an aquatic facility?

An aquatic facility is a physical place that contains:

  • One or more aquatic venues (for example, hot tubs/spas and pools) and
  • Support infrastructure (for example, chemical storage area).

Hot tubs/spas with tiled or painted finish or made of prefabricated shell materials, such as fiberglass and stainless steel:

  1. Clean accessible surfaces, scrubbing away slime and biofilm.
  2. Apply a biocidal shock treatment.
  3. Drain and remove water from the system.
  4. For hot tubs/spas with cartridge filters, remove the filter elements and leave them to dry.
  5. Shut down hot tub/spa, following manufacturer recommendations. This includes but is not limited to removing and storing probes.
  6. Keep hot tub/spa as dry as possible and protect it from external water sources (for example, hoses).
    • If in-ground hot tub/spa is installed in an area where ground water levels are extremely high and hot tub/spa shell is not designed to withstand hydrostatic ground forces:
      1. Consult with company or engineer that designed aquatic facility;
      2. Confirm that groundwater is below hot tub/spa before draining;
      3. Refill hot tub/spa with cool or cold water from potable water source; and
      4. Continue to discourage use of re-filled hot tub/spa with appropriate signage, barriers, or approved covers as described in CDC’s Model Aquatic Health Code (element 5.4.1.1.3).

Hot tubs/spas with plastered finish

  1. Clean accessible surfaces, scrubbing away slime and biofilm.
  2. Apply a biocidal shock treatment.
  3. Drain and remove water from the system.
  4. For hot tubs/spas with cartridge filters, remove, clean, and replace filter elements, as recommended by manufacturer.
  5. Shut down hot tub/spa, following manufacturer recommendations. This includes but is not limited to removing and storing probes.
  6. Refill hot tub/spa with cool or cold water from potable water source.
  7. Continue to discourage use of refilled hot tub/spa with appropriate signage, barriers, or approved covers as described in CDC’s Model Aquatic Health Code (element 5.4.1.1.3).

Before reopening the hot tub/spa, refer to appropriate guidance on building water systems. Check for existing regulations and guidelines from your local or state regulatory agency before using these recommendations. They do not replace

  • Existing regulations or guidelines from your local or state regulatory agency or
  • Consultation with a service company or the company or engineer that designed the aquatic facility.
Page last reviewed: April 21, 2020