Cyanuric Acid

Cyanuric Acid (CYA) is a chemical commonly used in outdoor pools to protect chlorine from being broken down by sunlight. However, in spas, especially indoor or covered spas, it’s generally better to avoid using CYA. Here's why:

1. Spas Don’t Need UV Protection:

• Since spas are often covered or indoors, there’s minimal UV exposure, so there’s no need to stabilize chlorine against sunlight degradation.

2. CYA Reduces Chlorine Effectiveness:

• In hot spa water, CYA binds tightly with chlorine, reducing its sanitizing power.
  This means even if you have enough chlorine in the water, it may not disinfect effectively, increasing the risk of bacteria and biofilm buildup.

3. Chlorine Lock & Sanitizer Inefficiency:

• High CYA levels can lead to “chlorine lock,” where the chlorine becomes inactive, even if test kits show adequate levels. This can result in cloudy water, odors, and poor sanitation.