Managing your pool’s Cyanuric Acid (CYA), also known as stabilizer or conditioner, is a delicate balancing act. Think of CYA as “sunscreen” for your chlorine; without it, the sun’s UV rays will destroy your chlorine in less than two hours. However, if your CYA levels climb too high, they “lock” your chlorine, making it impossible to kill algae and bacteria.
Use our Pool Stabilizer Calculator to determine if you need to add conditioner to protect your chlorine or if you are in the “danger zone” and need to drain water to prevent a green swamp.
Cyanuric Acid (CYA) Calculator
How to Use the Cyanuric Acid Calculator
- Pool Volume: Enter the total gallons of your pool.
- Current CYA Level: Use a high-quality test kit (like a Taylor drop test) to find your current ppm. Note that many test strips only go up to 100 ppm.
- Target Level: For standard chlorine pools, aim for 30-50 ppm. Saltwater pools usually require 60-80 ppm to help the generator keep up.
Why We Built This: Avoiding the “Chlorine Lock” Trap
The “Secret Sauce” of our tool is the High-Level Drain Logic. Most online calculators will incorrectly tell you how much CYA to “add” even if you are already over 100 ppm. This is dangerous. Once your CYA is too high, chlorine becomes chemically inhibited.
Our tool recognizes this “Swamp Risk” and calculates exactly how much water you need to drain and refill to bring your chemistry back to a safe, sanitizable range.
Educational Guide: The CYA/Chlorine Ratio
Understanding CYA is the difference between a crystal-clear pool and a green headache. To keep a pool sanitary, your Free Chlorine (FC) level must be at least 7.5% of your CYA level.
Tips for Managing Stabilizer
- Add it Slowly: CYA takes 3–5 days to fully dissolve. Never re-test your water immediately after adding stabilizer, or you will over-dose it.
- The Sock Method: Never pour CYA directly into the skimmer or the pool. Put it in a mesh sock and hang it in front of a return jet, or place the sock inside the skimmer basket to dissolve safely.
- Watch Your Puck Usage: Chlorine “pucks” (Trichlor) contain CYA. Every time you add a puck to your skimmer, your CYA level rises. This is why many pools turn green in late August—the CYA has climbed too high from months of puck usage.
Frequently Asked Questions
Q: How do I lower Cyanuric Acid without draining?
A: Unfortunately, there is no chemical way to lower CYA. It does not evaporate. Draining and refilling with fresh water is the only reliable method, though some specialized (and expensive) reverse osmosis services exist in certain regions.
Q: What happens if CYA is 0?
A: If your CYA is zero, your chlorine will be completely burned off by the sun within 1-2 hours. You will find yourself constantly adding chlorine and still waking up to cloudy water.
Q: Is Cyanuric Acid toxic to swimmers?
A: In standard pool concentrations (30-80 ppm), it is safe. In fact, it reduces the aggressive nature of chlorine on the skin and eyes by regulating how much “Active” chlorine is present at any given moment.
