There are smooth edges in my hot tub, what can I do to fix this?

1. Biofilm
Biofilm is a thin, viscous layer that adheres to the tub and pipes. It's resistant to chlorine and UV light, so rinsing won't help. Biofilm is created by soap residue, body oil and lime that accumulate in the water.

What can you do about biofilm?

• Make sure the water values are always correct: this reduces the risk of biofilm.
• Never use soap or bath products in the hot tub. Shower beforehand to remove any leftover body lotion or deodorant.
• Use Spa Balancer to prevent biofilm formation. This product encapsulates bacteria, oils and dirt so that it is removed via the filter.
• Use Ultrashock to remove existing biofilm. The agent breaks down the polysaccharides that form the biofilm.
  Note: if biofilm has been present for a long time, removal can take several months.

A good start is a basic cleaning with SpaBalancer and Ultrashock. Keep using it until the smooth layer disappears.

2. Algae growth
When it comes to algae, you'll notice this quickly — the edges feel smooth and the water can become cloudy.
In that case, enter a chlorine shock out and add algaecide as soon as you refill the hot tub.

If the smooth edges don't disappear, it's probably biofilm and not algae. In that case, you should continue with the treatment described above.

This way, you can keep the hot tub clean, smooth tarnish-free and the water clear and fresh again.