Bioflim Guide

What is Biofilm and what causes it?

Biofilm is a layer of bacteria that usually forms on spa surfaces and inside pipework. The warm and wet conditions in a hot tub are the perfect for biofilm to grow.

How does Biofilm form?

There are 5 main steps to the formation of Biofilm: 

1. 1. Biofilm attaches to a surface
2. 2. Biofilm develops on surface
3. 3. Biofilm protects itself against infection and attack
4. 4. Individual Biofilm grows in size
5. 5. Fragments break off and attach to new surfaces, expanding surface area

What does it look like and how can I detect if my spa is infected?

Biofilm is a slimy form bacteria and can often produce a sticky residue which makes it very difficult to remove.

Biofilm can attach itself to just about any surface in the spa. You could find it on the surface of your spa, walls and base, steps treads, safety rails, chemical dispenser, filter tank, pumps, pump impellers, heater plumbing and more commonly throughout the pipe work.

Bacteria that passes through the filter and is circulated will not have any colour, smell or taste detectable to the user. Generally, the only time users become aware is when their water begins to smell (a little bit like a rotten egg!), or when it begins to appear on surfaces.

What damage can Biofilm do?

Health Damage

Spas jets often create sprays and mists which if inhaled, could expose your lungs to the bacteria forming in your spa. This can potentially lead to Legionnaires disease which if left untreated, can result in fatalities within days.

Spa Damage

• Biofilms in spas can make your spa water cloudy.
• Biofilms are very acidic and this will corrode metal surfaces, such as your pumps, heater, jet furnishings, ladders and filter parts. Biofilms can be particularly damaging to the pipe work in your spa, causing corrosion and in some cases severe blockages.
• Biofilm can cause your spa to foam.
• Biofilm will is more commonly found on develop on the spa filters – they feed on dead skin and other particles that gather together on your filters. Unfortunately, when this happens your filters are rendered useless. Biofilm blocks the pores in the filter reducing the water flow. If your filters are not cleaned/changed often, the reduced water flow over time damages the heaters.

How can you prevent Biofilm?

The best way to prevent biofilm (and many other spa problems) is to ensure that your water is adequately sanitised. For more information on sanitising your water, see our sanitiser guide here.

• Brush your spas surface regularly, ideally on a weekly basis. Brushing breaks up the biofilms protective shield and lifts it off from the surface, allow the your sanitiser to kill it, and your filter to remove it.
• Clean your filter on a regular basis. If your filter is doing its job well, it will catch the Biofilm and prevent it from passing through the spa again. Always wear protective gloves when cleaning your filter, as your filter is full of bacteria. Avoid any contact with your mouth or eyes.
• Change your water regularly
• Flush your spa with a Biofilm eliminator at least once or twice a year, ideally at the end or beginning of a season.