CYA under 30 with cold water

Vtfanatic

Well-known member
May 17, 2015
57
Herndon/va
#1
I just opened my pool in VA so water temp is cold. I have not checked CYA yet, but if it is below 30 do I turn on heater to warm up water and then recheck or add stabilizer? My original plan was to get water right before turning on heater. Thanks in advance
 

duraleigh

Admin
Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
31,327
Sebring, Florida
#2
Do the test. The affect of cold water on the CYA test is largely overblown. It does exist but can be mostly ignored.

Do a CYA test at whatever temperature your pool water is.

Now, take a sample from your pool but take it indoors and warm it roughly to room temp and take the test again. Report your results.
 

faby3003

LifeTime Supporter
Jul 14, 2011
244
St. Paul, MN
#3
My understanding is that you just need to let your sample of pool water heat up to 70 degrees for the CYA test to be accurate. You don't need to heat the whole pool to 70 degrees.
 

Vtfanatic

Well-known member
May 17, 2015
57
Herndon/va
#4
CYA at room temp was 90 while taken indoors. Can I do it indoors and get an accurate reading? I struggled with CYA a ton last year as I was using the pucks for the first part of the year until reading that was the cause of the high CYA. I guess I was hoping by draining so much water out for closing the pool that it would have corrected itself. Granted the pool is full given the rain that we've had. How much water do I need to drain?
 

jblizzle

Mod Squad
TFP Expert
LifeTime Supporter
May 19, 2010
41,197
Tucson, AZ
#5
If your CYA is 90 and the typical targets are 30-50ppm, then you are looking at needing to replace 50% of your water ... assuming you are not running a SWG.