BIOFILM: What is it? Removal and Prevention

Biofilm is the rapidly reproducing of colony microorganisms surrounded by their protective slime in an aqueous environment.

They grow on the surfaces where the water doesn’t flow and prefer environments where water is stagnant and void of sanitizer. In hot tubs, they are often found in pipes where the water flow has been stopped or dramatically reduced (divider valves isolate certain therapy returns, waterfalls where flow has been shut off, ect) Biofilm is noticeable after water flow is returned to isolated pipes and is ‘blown’ back into the hot tub in the form of floating particulate that appears as tiny pieces of ‘skin’ or torn up pieces of tissue paper.

Removal: Do not use the hot tub during this process

  1. Ensure that water is flowing freely through the pipes, waterfalls, etc, and leave this way for during of treatment period.
  2. Properly balance the hot tub water with particular attention to balancing the pH to within the proper range of 7.4 – 7.6. Test periodically over the next 3 – 5 days to ensure pH continuously stays with this range.
  3. Elevate chlorine or bromine residual to 5.0 ppm or higher. Do not exceed 10 ppm. Maintain elevated level for the next 3 – 5 days.  Use Dazzle Bromine Granules or Dazzle Chlorine Granules to boost the level and maintain it. Test regularly to ensure level stay above 5 ppm.
  4. Apply 150 mL of Dazzle Algae Clear 60 per 1000 L of hot tub water.
  5. Run the pump periodically over the next 3 – 5 days to flush the pipes and keep biofilm circulating in the water as much as possible.
  6. After a minimum of 3 days, if the water is clear and the signs of bifilm have diminished or are gone, move to the next step. If not ensure step #2 and #3 are still in check and repeat step #4.
  7. Once visible signs of biofilm are gone after 5 days, stop additions of chlorine or bromine as in #3 above and allow the residual to lower to less than 5.0 ppm.
  8. With chlorine or bromine level less than 5.0 pp,, apply 1 bottle of Dazzle Drain Prep, as per label directions. Remove the filter cartridge and wait 2 days before moving to the next step.
  9. Clean your filter cartridge with Dazzle Filter Cleanse as per label directions.
  10. After 2 days, drain the hot tub, clean the inside of the tub with Dazzle Tub Cleanse and follow proper procedure for refilling the hot tub.


  1. Always return diverter valve to the position that allows flow through all return fitting after hot tub use.
  2. Use Dazzle Stain and Scale 1 with every fresh fill as per label directions.
  3. Use Dazzle Stain and Scale 2, Dazzle Amaze, and Botanical Cleanse weekly as per label directions.
  4. Continuously maintain pH and chlorine or bromine level in proper ranger.
  5. Use Dazzle Prep Drain prior to each drain as per label directions.


biofilm in spa jet
Photo: Biofilm in a spa jet


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