Biofilm
Biofilm is a protective matrix of bacteria and organic material that establishes on pool and spa plumbing surfaces.
Definition
Biofilm is a protective matrix of bacteria and organic material that establishes on pool and spa plumbing surfaces.
Typical Values: Address with pipe flush product before each hot tub drain and refill
In Plain Language
Biofilm forms when bacteria adhere to surfaces and produce a polysaccharide matrix that protects them from sanitisers. In pool and spa plumbing, biofilm colonises the inside of pipes, jets, and heater components. Biofilm is resistant to normal chlorine levels and requires periodic mechanical disruption (line flush products) or periodic high-dose treatments. Flushing the plumbing before a spa water change is the most effective routine treatment.
Why It Matters
Biofilm is a persistent source of organic contamination that recontaminates fresh water almost immediately if not addressed during a water change.
Typical Values
Address with pipe flush product before each hot tub drain and refill
Last reviewed: 2026-06-01