Cyanuric Acid Pool Calculator

Pool Volume

Volume Unit

Current Cyanuric Acid ($\text{PPM}$)

Target Cyanuric Acid ($\text{PPM}$)

Required Cyanuric Acid ($\text{CYA}$)

CYA Increase Needed ($\text{PPM}$)

Stabilizer Needed

What is Cyanuric Acid and Why Does It Matter?

Cyanuric acid acts as a chlorine stabilizer in pool water. It binds with free chlorine molecules, protecting them from sunlight degradation while keeping enough chlorine active to disinfect the water. The right CYA level ensures chlorine performs efficiently without being wasted.

Recommended Cyanuric Acid levels:

For outdoor pools: 30 to 50 ppm
For saltwater pools: 60 to 80 ppm
For indoor pools: 0 ppm (not needed as there is no sunlight exposure)

If the level is too low, chlorine burns off quickly.
If it’s too high, chlorine becomes trapped and less effective.
That’s why keeping your CYA within the right range is crucial for water balance.

Why Use a Cyanuric Acid Pool Calculator?

Calculating how much stabilizer to add can be confusing because it depends on:

Pool volume
Current CYA level
Desired target level

Adding too much stabilizer can take months to correct because CYA doesn’t evaporate or break down easily. The Cyanuric Acid Pool Calculator eliminates the guesswork. It calculates the exact amount of stabilizer (cyanuric acid) needed to reach your desired CYA level safely and accurately.

This tool is especially helpful when:

You’re opening your pool after winter
You’ve just refilled or partially drained it
You’re trying to optimize chlorine use during peak sunlight months

How the Cyanuric Acid Calculator Works

The calculator uses your pool volume and the difference between your current and target CYA levels to determine the correct amount of stabilizer to add.

You simply enter:

Pool Volume – in gallons or liters
Current Cyanuric Acid (ppm) – the level measured in your pool
Target Cyanuric Acid (ppm) – your desired level

Then click “Calculate Stabilizer Amount.” The calculator instantly provides:

The CYA increase needed (in ppm)
The stabilizer weight required (in pounds and kilograms)

It’s fast, accurate, and tailored to your specific pool setup.

How the Formula Works

Here’s a simplified breakdown of the calculation:

Stabilizer Needed (lbs) = (CYA Increase × Pool Volume in Gallons) ÷ 10,000

For metric measurements, the calculator converts pounds to kilograms automatically using the constant:
1 lb = 0.453592 kg

This ensures accurate results whether your pool is measured in gallons or liters.

Example Calculation

Let’s say you have a 15,000-gallon pool with a current CYA level of 30 ppm, and you want to increase it to 50 ppm.

CYA increase = 50 – 30 = 20 ppm
Stabilizer needed = (20 × 15,000) ÷ 10,000 = 30 lbs
That equals roughly 13.6 kg

So, to reach your target level, you would add about 30 pounds (13.6 kg) of cyanuric acid.

How to Add Cyanuric Acid Safely

Turn on your pool’s circulation system.
Ensure water is moving to help distribute the chemical evenly.
Dissolve the stabilizer (optional).
Some pool owners prefer to pre-dissolve it in a bucket of warm water before adding. Others pour it directly into the skimmer or filter area.
Add it slowly.
Pour in small amounts over time to avoid clumping or residue buildup.
Allow 24–48 hours for full mixing.
Don’t retest immediately; stabilizer takes time to dissolve and register accurately.
Retest your water.
After two days, check CYA levels and make small adjustments if needed.

Common Mistakes to Avoid

Adding too much stabilizer at once – It’s easier to increase CYA than to lower it. Add in small increments.
Testing too soon – Wait at least 24 hours after adding before retesting.
Ignoring pool volume – Always use accurate pool capacity measurements for reliable results.
Confusing stabilizer with shock – These are separate chemicals with different functions.