Bio-films are turning out to be the root cause of most spa & hot tub "problems." That's why those problems are difficult to get rid of - they are almost always undetected.

Bio-films in spas & hot tubs lead to cloudy water, foaming, odors, scale build-up on the heater (prevents efficient heating), and even corrosion (certain biofilms can have a pH of about 1.0 - very acidic) of any metal surface of the circulation system including heaters, filter parts, rails, etc.  Bio-films can even lead to the degradation of spa pillows, covers & other accessories.

The same thing applies to jetted bathtubs & whirlpools!

Bio-films are films or large quantities of bacteria living as a vast colony in the microscopic world. In our "big" world, a coral reef could be considered "bio-film." Bio-films are self-perpetuating & difficult to remove. Worst of all, bio-films grow on any surface, especially wet or damp. Warning: even after drying out, the bio-film is not dead but only dormant.

Bio-films form on any surface. In your spa or hot tub that means the seats, walls, bottom, skimmer baskets, filter cartridge and filter well, tank bodies, pump bodies and impellers, jets, handles, lights, air holes, heater plumbing, and especially the piping. There is a 5 steps process in the formation of bio-films as shown in the diagram above. Let's look at them.

1. Attachment: the bacteria attaches to the surface. It wants to attach & grow. Bacteria want to be in relationships, so they find a surface, any surface, to attach & breed.

2. Colonization takes place as bacteria multiply and divide, therefore growing quickly & in great numbers. According to university studies, this is the crucial point where attachment is considered "irreversible." The bacteria colony is staying unless removed. Colonization is accomplished in a matter of minutes or hours at most!

3. Protection: the bacteria colony or bio-film protects itself against invasion from environmental factors, "lethal" chemicals (such as chlorine or bromine), predators, or anything that want to destroy it. Technically, the bacteria begins to excrete a protective coating called an "exopolysaccharide" film. This film is sticky or slimy and very tough. Now with this protection, the biofilm experiences phenomenal growth.

4. Growth: like a coral reef, the bio-film gets bigger & tougher. "Super colonies" of bio-film actually absorb certain chemicals (such as chlorine) that were meant to destroy them.

5. Distribution: as the bio-film becomes "too big," parts break off &begin to attach to other surfaces or different parts of the same surface. And the bio-film cycle begins again.

Bio-films are everywhere: Pools, spas, bathrooms, kitchens, the funky look to your patio furniture, on your teeth (plaque is a bio-film), wherever there is a surface that is damp, there's a bio-film.

What do you do? Bio-films are resistant to chlorine & bromine. Bio-films bond with biguanides. Ionizers have no effect. You have to remove it.

The picture to the left shows a brand new spa having the bio-film removed over several hours. But how? Products such as AquaFinesse, Natural Chemistry Spa Purge, Spa System Flush or Swirl Away can do the job.

Bio-film lifecycle image courtesy of: prometheus.mse.uiuc.edu