Refilling due to CYA: Free Chlorine at 13 ppm and green?

CYAnxious

Member
Jun 9, 2021
10
Western New York
Pool Size
32000
Surface
Vinyl
Chlorine
Liquid Chlorine
Hello!
I am draining and refilling some of my water due to having CYA of about 100. I did about a third, since we've had very very heavy rainfall and I've had to pump water out several times in the last few days already. I'm still refilling, and have about 3 inches above the skimmer line to go. I tested the water earlier out of curiosity and since I was extremely chlorine-locked with a green pool my chlorine was at 13ppm! 0 combined chlorine, 7.2 Ph, TA at 70.

My question is, what do I do about such high chlorine? Do I wait until its all filled up and retest? Once chlorine is "locked" is it unusable no matter the CYA concentration? After about 2 hours of refilling my CYA was at 80, and like I said, I've got several more hours to go and my pool is GREEN. But, I want to get rid of my green pool ASAP. If CYA is "diluted", will the chlorine work or is it spent and I just need to wait till it burns off? Im sorry if this seems silly, I'm still trying to figure all this out! Thank you!
 

Texas Splash

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Chlorine lock is an industry term has no bearing here at TFP. Basically, chlorine is either balanced to the CYA as noted on the FC/CYA Chart or it's not. If your CYA is currently 80, then your FC can be much higher - the SLAM FC level is 31 based on that CYA per the FC/CYA Chart. So if your pool is green from algae, then you simply need to increase the FC to 31 and perform the SLAM Process. Now if you are on a well and the green is related to iron versus algae (or both) then things get a little tricky. But for algae, it's all about the FC/CYA Chart.
 

willygee

Silver Supporter
Aug 24, 2020
180
central fla
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"Chlorine lock is an industry term has no bearing here at TFP"....as quoted above..i used the phrase before but no more. For almost a year my CYA was 100 (now 60) as prior owner tabbed to much. Used TFP"s FC/CYA chart and set FC between 7 and 11ppm....water has always stayed clear.
 

CYAnxious

Member
Jun 9, 2021
10
Western New York
Pool Size
32000
Surface
Vinyl
Chlorine
Liquid Chlorine
Chlorine lock is an industry term has no bearing here at TFP. Basically, chlorine is either balanced to the CYA as noted on the FC/CYA Chart or it's not. If your CYA is currently 80, then your FC can be much higher - the SLAM FC level is 31 based on that CYA per the FC/CYA Chart. So if your pool is green from algae, then you simply need to increase the FC to 31 and perform the SLAM Process. Now if you are on a well and the green is related to iron versus algae (or both) then things get a little tricky. But for algae, it's all about the FC/CYA Chart.
Thank you, I'll remove it from my vocabulary. Let me see if I understand this correctly. My CYA started very high, and so it doesn't matter that my chlorine is currently at a 13, it won't sanitize the way it needs to due to over-stabalization.
I think im also having a hard time articulating my question due to my lack of knowledge.

Should I increase my chlorine or just wait and work on my CYA? I guess what I'm asking is, if high CYA renders my current chlorine essentially useless, and I continue to refill, will the level of chlorine I have currently be useful at all if it becomes more balanced to the CYA, or is it really "wasted" ( this is where I'm inclined to use the term "chlorine-lock"; does CYA bind to Chlorine? I guess I just don't understand their interaction on a chemical level) at this point and I'll have to raise it all over again? I understand that I could just keep up my free chlorine at a higher level, but I'd rather drop the CYA and use less. I'm not on well, and it's certainly algae. Previous owners only used pucks.
 

reggiehammond

Gold Supporter
Oct 4, 2020
375
Fort Worth, Texas
Pool Size
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Thank you, I'll remove it from my vocabulary. Let me see if I understand this correctly. My CYA started very high, and so it doesn't matter that my chlorine is currently at a 13, it won't sanitize the way it needs to due to over-stabalization.
You understand the trickiest part - Congrats. FC levels are completely dependent on CYA level.
My 3 year old swims with no goggles, eyes open underwater, in FC levels near 10. This blows peoples’ minds until you understand the CYA relationship.
 
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CYAnxious

Member
Jun 9, 2021
10
Western New York
Pool Size
32000
Surface
Vinyl
Chlorine
Liquid Chlorine
Get your CYA to 50 ppm or so. Then follow the SLAM Process
Will do. Hopefully I'll be there by tomorrow. I won't worry about anything else until CYA is in the right place. I'm so sick of using so much chlorine to maintain a clear pool and I wish someone had told me 2 years ago to get rid of these pucks. Even though I barely used them, the previous owners used them as their primary maintenance method.
 

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
Jun 22, 2014
33,643
Texas, San Antonio/Marion, South-Central Area
Pool Size
17888
Surface
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Chlorine
Salt Water Generator
SWG Type
CircuPool RJ-45 Plus
I wish someone had told me 2 years ago to get rid of these pucks.
And it's frustrating the stores will be happy to keep selling them with no warning about your CYA until they say ....."Time to drain". :brickwall: But now that you know and once you lower that CYA, this won't be an issue again.
 
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