Hot tubs require a full drain-and-clean every 3–4 months regardless of how often the water is treated. Biofilm builds up in the plumbing lines, the shell accumulates scale and grime at the waterline, and the filter collects debris that reduces its effectiveness. Proper cleaning takes a few hours but preserves the equipment and prevents health issues from contaminated water.
Step 1: Flush the Plumbing Lines
- With the tub still full, add a hot tub pipe flush product (available at pool and spa stores) and run the jets on high for 30 minutes — this flushes biofilm from the internal plumbing lines before draining
- The water will likely become discoloured — this is the biofilm being dislodged; it's normal and expected
Step 2: Drain
- Turn off power at the breaker panel
- Drain using the built-in drain valve (usually on the lower side of the cabinet) or a submersible pump for faster draining
- Remove the filter cartridge(s)
Step 3: Clean the Shell
- Use a hot tub shell cleaner (non-foaming, spa-specific) or a diluted white vinegar solution on the interior surfaces
- Scrub the shell with a non-scratch pad — focus on the waterline where scale and oils accumulate
- Wipe clean with a damp cloth and rinse with a garden hose
- Use a dry cloth on the jets and fittings
Step 4: Clean the Filter Cartridge
- Rinse the filter with a garden hose, spraying between each pleat to remove loose debris
- Soak in a commercial filter cleaning solution overnight, then rinse thoroughly
- Allow to dry before reinstalling — a wet filter inserted while refilling can cause flow issues
- Replace the filter completely every 12–18 months even with regular cleaning
Step 5: Refill and Balance
- Refill with fresh water using a garden hose — place the hose in the filter compartment to minimize air locks in the plumbing
- Turn power on and allow to heat
- Test and balance the water: adjust pH to 7.2–7.8, alkalinity to 80–120 ppm, and add sanitizer (chlorine or bromine) per the product directions
- Run the jets for 30 minutes before first use