CYA for SWG

Lykly

Gold Supporter
Nov 6, 2015
888
Ok ok
#1
OK, I am ready to convert my pool to a SWG. Currently my CYA is it 35. I know by reading it should be higher for a SWG, but I'm curious how high and why? I understand I have to maintain a higher chlorine level with a SWG as a result of higher CYA? Trying to learn..... Thanks.


Sent from my iPhone using Tapatalk
 

pooldv

Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
Aug 10, 2012
24,976
DFW, TX
#2
Higher CYA protects chlorine from the sun better and lets the SWG work less and with continuous doses over periodsmof many hours through the day you can get away with lower levels. I keep mine at 80. See bottom half of chart for SWG, Chlorine CYA Chart
 

Lykly

Gold Supporter
Nov 6, 2015
888
Ok ok
#4
Man that is way over my head, although very interesting. I can't believe how much time and effort some people put into helping others, that is awesome.

Bottom line is, I'm trying to figure out how much CYA to put in my pool, I don't want to get too much but I want enough. Would 60 ppm be reasonable? When I bought this house the CYA in the pool was over 300, which contributed to ruining the plaster I believe. So naturally I am cautious of too much. I know the chart recommends minimum 70, but I believe others are using less with SWG?


Sent from my iPhone using Tapatalk
 

pooldv

Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
Aug 10, 2012
24,976
DFW, TX
#5
My pool has a little over 80 ppm of CYA. If I were you I would put 80 ppm in your pool too. The only downside to using less CYA is that you will lose more FC to the sun. So, for example, maybe you will lose 2 ppm with 80, 3 ppm with 70 and 4 ppm the 60. I understand being nervous about CYA with your past experience. But, CYA is your friend. It protects chlorine which is an even better friend.
 

Lykly

Gold Supporter
Nov 6, 2015
888
Ok ok
#6
thanks, I will continue to raise it. I have a couple pounds in the skimmer via a sock right now, I will let it get dissolved and check level so I don't over shoot but I will target for 70-80.


Sent from my iPhone using Tapatalk
 

fordsbyjay

LifeTime Supporter
Sep 1, 2009
65
Lafayette, LA
#8
70-80 is what you need. Being you have stuff in the skimmer now I would convert to SWG and adjust the CYA as it goes. Essentially the CYA helps keep chlorine in the pool and is directly correlates with the CL level. If your CYA is too low you CL will be low to none and algae will become an issue. The SWG system makes your pool water very forgiving to be honest and once your salt water level is around 3200 your chemicals can be off and you will still have a nice pool; too the point where you get lazy on the testing. lol.
 

Lykly

Gold Supporter
Nov 6, 2015
888
Ok ok
#9
According to my K1766 kit salt is at 3400 currently. I will check CYA as the additional added is now dissolved. Not sure it has the time to distribute throughout the pool though. Last time it took a few days to get the true reading. Hopefully tomorrow the SWG will be operational, I was hoping it would've been already but they needed to get a specific timer. I have been keeping the chlorine at 5 manually. Once I get the stabilizer where it needs to be I will check the chart for proper chlorination levels.


Sent from my iPhone using Tapatalk
 

Lykly

Gold Supporter
Nov 6, 2015
888
Ok ok
#10
CYA is sitting at 40, I'm guessing it is still on the rise. It just finished dissolving in the sock sometime during the night. By my calculations it should approach 60 with what I've added. I want to crawl up to 70 as I don't want to exceed what is needed.


Sent from my iPhone using Tapatalk
 

JayBauman

LifeTime Supporter
Sep 5, 2014
617
Katy, TX
#11
With the large amount of rains we have had since I first opened my pool a year and a half ago, my CYA levels have fluctuated between 60 and 90. I definitely notice that I have to turn my duty cycle (% runtime) down when I'm at the higher levels of CYA. Clearly, my chlorinator is working harder at the lower levels, which means higher electricity bills and shorter lifetime from my SWG cell. Listen to pooldv and keep it at the higher levels.
 

Lykly

Gold Supporter
Nov 6, 2015
888
Ok ok
#12
My pool has a little over 80 ppm of CYA. If I were you I would put 80 ppm in your pool too. The only downside to using less CYA is that you will lose more FC to the sun. So, for example, maybe you will lose 2 ppm with 80, 3 ppm with 70 and 4 ppm the 60. I understand being nervous about CYA with your past experience. But, CYA is your friend. It protects chlorine which is an even better friend.
Thanks Pooldv. I will follow your advice.
 

pooldv

Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
Aug 10, 2012
24,976
DFW, TX
#13
CYA should show up on the test 24 hours after it is dissolved from the sock. You can wait 48 hours to be on the safe side.
 

Lykly

Gold Supporter
Nov 6, 2015
888
Ok ok
#15
I'm having a hard time figuring out what's up with my CYA. Based on additional salt, I figured my pool to be around 13K gallons. But based on the addition of my CYA, it must be more than that. Curious what I should be figuring my pool size out in reference to salt addition or CYA addition? According to salt addition it's around 13,000 gallons according to CYA it's looking more like 15,000 gallons. I added a total of 8 pounds of CYA, 4 days after my last addition of CYA, my CYA is right around 60 ppm. We have had some rain, but I can't imagine enough to make much difference. Unless I'm reading my CYA test incorrectly, I follow instructions, and add until I absolutely cannot see any sign of that black dot. Before I add anymore, any suggestions? Thx


Sent from my iPhone using Tapatalk
 

Griswald

Well-known member
Jul 7, 2014
641
Hope Mills, NC
#16
Since my pool is covered almost all the time, I keep my CYA at around 60. I also have my SWG set to 32% and that holds my FC jst fine. All of the numbers are guidelines, your numbers can vary as long as you test and maintain.

Wait a few days before checking CYA it doesnt show right away.
 

Lykly

Gold Supporter
Nov 6, 2015
888
Ok ok
#17
Since my pool is covered almost all the time, I keep my CYA at around 60. I also have my SWG set to 32% and that holds my FC jst fine. All of the numbers are guidelines, your numbers can vary as long as you test and maintain.

Wait a few days before checking CYA it doesnt show right away.
Thank you for the reply. I have added CYA over the last couple of weeks, the last addition was two days ago, so I'm thinking after 48 hours it should be registered. You say you have your saltwater generator set at 32%, how many hours a day does it run? How many gallons is your pool? Sorry if it's in your sig., I'm using my iPhone and it does not show Sig's.


Sent from my iPhone using Tapatalk
 

needsajet

TFP Expert
LifeTime Supporter
Jan 4, 2016
4,548
Sydney, NSW, Australia
#18
If it were me, I'd trust the salt as an indicator over the CYA because of higher test error. I'd also log all chem additions and see over time and quite a few chem additions if I need to change the volume. In the meantime, I'd be happy with approximate as Clark mentioned.
 

Griswald

Well-known member
Jul 7, 2014
641
Hope Mills, NC
#19
Thank you for the reply. I have added CYA over the last couple of weeks, the last addition was two days ago, so I'm thinking after 48 hours it should be registered. You say you have your saltwater generator set at 32%, how many hours a day does it run? How many gallons is your pool? Sorry if it's in your sig., I'm using my iPhone and it does not show Sig's.


Sent from my iPhone using Tapatalk
My pool is 17000 gallons and the pump runs 12 hours
 

Lykly

Gold Supporter
Nov 6, 2015
888
Ok ok
#20
I added another pound the night before last, and I'm still only seeing 60 ppm. I'm going to stop adding as I know there has to be at least that much in there. I do the test the same way every time until I absolutely cannot see the dot. I brought a water sample to two different Leslie pool stores today to see what they were get , one said 35, the other said 70, so that was a complete wasted two trips. LOL anyway, I'm done adding CYA and I know I have a minimum of 60 ppm so I should be good.


Sent from my iPhone using Tapatalk