How does one decide target CYA for your location/season?

cbaird99

Member
Jul 12, 2019
5
Texas
I am trying to educate myself more about my pool now that I am doing my own testing. I am using the Pool Math app to log everything prior to doing my first slam probably this weekend. Is the app choosing my target CYA for me, it seems to be? Or should I know how to set the target myself. I am seeing some posts in which people are adjusting their target CYA if it is super sunny/hot which my pool is (DFW Texas)...I know how impt. this number is for everything else, and I did not realize that I would WANT it to be higher. Is it flexible, and if so how do I decide where I should be year round?? This stuff is complicated but I am trying:)
 

jblizzle

Mod Squad
TFP Expert
LifeTime Supporter
May 19, 2010
43,255
Tucson, AZ
You need to set all the targets for yourself. The app might have some defaults, but they are not necessarily universal.

In TX, I would suggest starting at 50ppm for CYA and seeing how much FC you are losing to the sun each day. It more than you like, increase the CYA a bit. Much lower than 50ppm and your FC loses are just going to be very high in the southern summer sun.
 

Lilypad

Bronze Supporter
Nov 12, 2016
189
Plano, Texas
My CYA is 50. It gives me some "wiggle room" when I go on vacation and use pucks in the chlorinator (as they will raise the CYA). I agree with jblizzle that 50 is a good target.
 

poolnoobgrandma

Well-known member
Sep 15, 2018
174
Seminole, FL
I was wondering the same thing, but in terms of UV protection provided by a screen enclosure. We are in sunny FL, and I was wondering if the screen enclosure offers enough UV protection to drop the target CYA just a bit.
 

elmorage

Well-known member
Jun 21, 2013
45
NY
My new pool is in full sun all day and 30-40 cya is not getting the job done. I am going through 6-10 fc each day and using tons of bleach each evening. I’m in the process of increasing to 50.
 

jblizzle

Mod Squad
TFP Expert
LifeTime Supporter
May 19, 2010
43,255
Tucson, AZ
I was wondering the same thing, but in terms of UV protection provided by a screen enclosure. We are in sunny FL, and I was wondering if the screen enclosure offers enough UV protection to drop the target CYA just a bit.
It should lower the UV losses some, and a lower debris load. So start with 30-40ppm and see how it goes.
I would think the amount of rain you get would quickly lower your CYA even if you got too high.
 
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ckendalls

Active member
May 17, 2018
26
Clermont FL
It should lower the UV losses some, and a lower debris load. So start with 30-40ppm and see how it goes.
I would think the amount of rain you get would quickly lower your CYA even if you got too high.
What jblizzle said. I was plenty fine at 50 CYA for my SWG in a screened enclosed pool here in Florida running 10% or less. I also have sun sails up now which probably help keep FC up a bit more. I know TFP recommends 70 for outdoor pools but I am sorry I went up tp 70 npw, although it does seem to have slowed my pH rise a bit.... Now at 70 my SWG is only running at 1% maintaining 4.5 FC, but my CSI is more aggressively negative... I want to let my CYA get back down to 50 or lower as I am not concerned about generating enough FC with this setup now and I want my TA lower than 70 to minimize acid additions.