CYA ????

[Hapiee]

Small, 3,500 gal Intex above ground pool. CYA is 88ppm and pool store told me to drain and refill. Hubby says it's not necessary to do that and it won't hurt us. I shocked the pool in the early am before the sun got bright then took a sample in to have it checked. Pool store clerk says it's to out of balance to test until the shock gets to work but that at 88 ppm I need to drain some water and refill.

We changed out the cartridge filter to a Hayward sand filter this season.

 

[jwhop3]

Think of cya as a chlorine retarder. It binds a certain amount to use later, so even though your test results might say your FC is adequate, or even high, you can still have an algea bloom. I have always kept mine at 50 ppm, once this summer mine got to ~70ppm, and I started chasing cloudy and green-tinged water. To know what you would need to drain, divide what you want by what you have, then subtract from 100. To get to 50ppm, 50/88 = 57% - 100 = 43%. That would be a significant drain, so it would be cheaper for you to just refer to the CYA/Cholrine demand chart and put in the required level for your cya reading.

 

[duraleigh]

Probably not much swim time left for you. I would just refer to the chart as above.

Next year keep your FC around 50 ppm.

 

[26venus]

Next year keep your FC around 50 ppm.

I think he meant CYA around 50

 

[duraleigh]

Sorry! Yes, CYA at 50.