Swimming pools have cyanuric acid (CYA) levels in the pool that slow the dissipation rate of free chlorine in a swimming pool. CYA helps to stabilize the water under the hot summer heat. The ideal range for CYA is 30 to 50 parts per million (ppm). Cyanuric acid does not evaporate under the hot sun. When its levels are high, you will need to lower them or risk chlorine lock if the acid level rises above 100 ppm.
Things You'll Need
- Cyanuric acid test kit
- Swimming pool sump pump
- Garden hose
Test the CYA level in the water before making any changes to the water. Use a cyanuric acid test strip. Dip the strip in the water and remove. Compare the color of the strip to the test kit color chart. If the acid level is above 50 ppm, continue reading.
Purchase or rent a sump pump for swimming pools. The pump is submergible so you can place it in the water while plugged into an outlet.
Attach a garden hose to the sump pump. Plug the pump into a grounded outlet. Place the pump in the water about 6 inches down. Use a brick or something heavy to lie down on the garden hose to keep the pump in place in the water. Watch the pump carefully. When you have taken 6 inches of water from the pool, remove the pump and unplug it.
Unwind the garden hose from the sump pump. Place the end of the hose in the pool. Connect the other end of the hose to your outdoor water faucet. Turn on the water and replace the 6 inches of water you removed.
Retest the water the next day after the pool filter has had a chance to run for at least eight hours during normal operation. If the water CYA level is still high, repeat steps 3 and 4 every day until the level drops into range.