How to Handle High Cyanuric Acid in Pools

Cyanuric acid (CYA) is a stabilizer that protects chlorine from breaking down in sunlight. However, too much CYA can weaken chlorine’s ability to sanitize your pool, leaving it vulnerable to algae and bacteria. Understanding why high CYA levels matter helps you act quickly.

Effects of Excessive CYA

• Reduces chlorine efficiency

• Makes water cloudy and unpleasant

• Encourages algae growth

• Leads to higher chlorine consumption

Tools and Supplies You Will Need

Prepare the right tools and materials to address high CYA effectively.

Essential Supplies

• Cyanuric acid test kit or strips

• Fresh water source for dilution

• Submersible pump or pool pump

• Bucket for dilution (if using chemicals)

• Optional CYA reducer product

Optional Extras

• Maintenance log to track water chemistry

• Protective gloves and goggles

Step-by-Step Guide to Lowering Cyanuric Acid

Follow these steps carefully to bring CYA levels back to the ideal range.

Step 1: Test the Water

• Use a reliable test kit or strips to measure the CYA level.

• Ideal range for CYA is 30–50 ppm for outdoor pools.

• Levels above 100 ppm indicate the need for corrective action.

Step 2: Stop Adding Stabilized Chlorine

• Avoid using chlorine tablets or granules that contain CYA.

• Switch to liquid chlorine or calcium hypochlorite until levels drop.

Step 3: Partial Drain and Refill

• Lower the pool water level by 6–12 inches or more, depending on how high CYA is.

• Use a fresh water source to refill the pool.

• Retest and repeat the process if necessary.

Step 4: Use a CYA Reducer (Optional)

• If draining is not practical, consider using a commercial CYA reducer.

• Follow the manufacturer’s instructions carefully.

• Be patient, as some products may take several days to show results.

Advanced Tips for Managing CYA

Monitoring Over Time

• Test CYA monthly, especially during summer.

• Keep a maintenance log to track trends and detect issues early.

Balancing Other Chemicals

• After lowering CYA, test chlorine, pH, and alkalinity.

• Adjust other levels as needed to maintain proper water chemistry.

Preventing High Cyanuric Acid

Once you correct high CYA levels, it’s important to prevent the problem from recurring.

Best Practices

• Use unstabilized chlorine whenever possible.

• Regularly monitor water chemistry and adjust accordingly.

• Avoid overusing chlorine tablets, which contribute to CYA buildup.

Seasonal Considerations

• During heavy pool use or after storms, test more often.

• Recheck after opening the pool each season to ensure balanced levels.

Safety Tips While Working on Your Pool

• Wear gloves and goggles when handling chemicals.

• Keep children and pets away from the work area.

• Do not drain water into areas that can flood or damage landscaping.

Helpful Notes

• Draining more than one-third of your pool at a time can risk structural damage, so drain in stages.

• Be mindful of local water restrictions and environmental regulations.

By following these detailed steps and tips, you can safely lower cyanuric acid levels in your pool and maintain clean, healthy water that’s comfortable and safe for swimming.