Is CYA only added so that one doesn't have to keep adding so much chlorine?

Ronkivxx

Member
Jul 6, 2020
7
Akron, Ohio
Basically I've got my pool water where I want it and after daily testing for a while all I have needed to do is add maybe 3 cups of bleach daily to keep the free chlorine levels where I want them. I have some CYA, but I don't want to use it if I don't have to (less things added to the pool, the better). I am okay with the amount of bleach I am using and with "topping it off" daily. Is there any other reason I should be using CYA, or am I good without it?
 

YippeeSkippy

Mod Squad
LifeTime Supporter
Jan 17, 2012
13,833
Evans, Georgia
Got some test results to share?
FC
CC
pH
TA
CH
CYA

The fast and dirty answer is yeah, it helps hold some chlorine in to protect the pool and keep FC in reserve. If the CYA is too high you won't be able to keep the FC effective as you'd need a LOT more. If the CYA is too low, the sun will burn off your chlorine and leave you vulnerable to algae.

Maddie
 

Msch99

Gold Supporter
Bronze Supporter
Jun 11, 2018
841
Verona, MO
Without any CYA your chlorine will go poof! 20 to 30 ppm in non salt pool works.
Why don’t you like cya?

please put your pool information in your signature so the experts can better help.
Also, what test kit do you use?
 

Ronkivxx

Member
Jul 6, 2020
7
Akron, Ohio
Haha, I knew the first thing said would be "got some test results?" I'll go do a test now, but off the top of my head my last test (done at the end of the day before adding the day's bleach) was:
Free Chlorine is at 2-ish
No Combined Chlorine
pH 7.8 ish
Total Alk I don't remember what it is at, but it was balanced as in it was not a problem.
CYA - nothing, obviously :)

I'll look and see exactly what test kit I have when I go test the water, but it was the best one they had at the local pool store (not counting the digital one). It has 5 liquid droppers and two water vials. To test FC and CC you drip 5 drops and after 30 sec is the FC, then after 2 min the change from the FC is the CC. total alk. depends on the FC test because you have to add chlorine neutralizer.
I added my pool info to my sig; thanks for telling me that.
I'll be back with better info in a bit.
 
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Ronkivxx

Member
Jul 6, 2020
7
Akron, Ohio
Okay, well I think I have my answer. :)
First off, my testing kit only does 4 tests- Free Chlorine, Total Chlorine, pH and total Alkalinity. After I write this, I'm probably going to go order a 5-in-one kit. Silly me to think that the local pool store's best test kit wouldn't be 5-in-one.

Here are my test results at the end of the day before adding any bleach.
FC - 0 (This would be my answer. Dang that chlorine broke down QUICKLY)
Total chlorine - 0 as well
pH 7.8 (I added some pH down, haven't retested yet)
Total alkalinity - 70ppm I think? The tester is reliant on being able to count how many drops you put in and the vial that you use for TA is messed up and won't do drops, so I'm estimating how many drops were in the stream it put out

In any event, I see that I need to add CYA. I have the granular stuff; I see here that one should put it in a sock and in front of the water jet. I THINK I remember it saying here that one should not run the filter for 24hr after adding CYA; I take that to mean I should set my pump to recirculate since turning it off completely would remove the water jet.
 

Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
23,870
San Dimas, CA (LA County)
You must have some CYA in the water, or your chlorine wouldn't last but an hour or two. If you've ever used the 3" pucks or the 1" tablets to chlorinate, or if you've ever used dichlor or trichlor "shock", you've added CYA.
 

wireform

Silver Supporter
In The Industry
Aug 15, 2017
1,425
Spring Valley, NY
Okay, well I think I have my answer. :)
First off, my testing kit only does 4 tests- Free Chlorine, Total Chlorine, pH and total Alkalinity. After I write this, I'm probably going to go order a 5-in-one kit. Silly me to think that the local pool store's best test kit wouldn't be 5-in-one.

Here are my test results at the end of the day before adding any bleach.
FC - 0 (This would be my answer. Dang that chlorine broke down QUICKLY)
Total chlorine - 0 as well
pH 7.8 (I added some pH down, haven't retested yet)
Total alkalinity - 70ppm I think? The tester is reliant on being able to count how many drops you put in and the vial that you use for TA is messed up and won't do drops, so I'm estimating how many drops were in the stream it put out

In any event, I see that I need to add CYA. I have the granular stuff; I see here that one should put it in a sock and in front of the water jet. I THINK I remember it saying here that one should not run the filter for 24hr after adding CYA; I take that to mean I should set my pump to recirculate since turning it off completely would remove the water jet.
No, you run the filter. You don't backwash for 2 days. I suggest order the TF-100 now so you don't loose another day. Use the to get SOME cya into the water but err on the side of caution as too much will mean more liquid chlorine.
 

Ronkivxx

Member
Jul 6, 2020
7
Akron, Ohio
You must have some CYA in the water, or your chlorine wouldn't last but an hour or two. If you've ever used the 3" pucks or the 1" tablets to chlorinate, or if you've ever used dichlor or trichlor "shock", you've added CYA.
Yeah, I suppose you're right, as at very first I used some "shock" but I'll bet it's not THAT much because that chlorine really goes away FAST as soon as I take the cover off. With the cover on all day, the chlorine barely drops. I've got some of those tabs but all I use to chlorinate now is bleach, since I found this site. :)
 

Ronkivxx

Member
Jul 6, 2020
7
Akron, Ohio
You need a proper test kit. I suggest the TF-100 A proper test kit is needed to get the accurate water chemistry results needed to follow the TFP protocols.
Yeah, when I said "order a 5-in-one", what I really meant was "I'm about to go order the test kit that you guys suggest but I can't remember what it's called right now", which would be the TF-100. The TF-100 is put together by TFP, right? As in if I order it instead of, say, a Taylor kit I'll be supporting TFP in some fashion? I really wish it were cheaper but I will say that it seems to be the best deal for what you get. Other comparable test kits seem to be much more expensive and I'm not trying to spend $250 on a test kit for my stupid coleman pool, y'know?
I will say that $17 extra for a pH tester is AWESOME- I've always wanted one but never really had a good reason to get one until now.
OK, off to order the TF-100 now.
 

mguzzy

Gold Supporter
Jul 8, 2015
2,040
OV, CA
The nice thing about the TFTest kits is the proportions of the reagents are more along the lines of what most residential pool owners use. The Taylor ones seem to have different proportions. They BOTH use Taylor reagents. So that's what makes the TF one a better deal.

We need to find out how much CYA is in your pool. CYA helps protect the chlorine from being degraded by the sun.. if you have an indoor pool is not as necessary because the pool is protected from the sun. That's why you see less chlorine loss when your cover is on. Hope that makes sense!
 
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Jeff J.

Well-known member
Aug 6, 2019
175
Staten Island NY
Basically I've got my pool water where I want it and after daily testing for a while all I have needed to do is add maybe 3 cups of bleach daily to keep the free chlorine levels where I want them. I have some CYA, but I don't want to use it if I don't have to (less things added to the pool, the better). I am okay with the amount of bleach I am using and with "topping it off" daily. Is there any other reason I should be using CYA, or am I good without it?
I've read on here that CYA also makes the chlorine less harsh on swimmers.
 

mgtfp

Bronze Supporter
Mar 5, 2020
278
Melbourne, Australia
CYA also allows to have a chlorine reservoir to get you through a day without having active chlorine levels (HOCl) that are sky high and aggressive on equipment and swimmers and their gear. That's why some CYA makes sense even in indoor pools.

In public pools without CYA they might start the day with 4ppm of FC to ensure that at the end of the day they still have 1ppm. The problem is, that 4ppm FC at 0ppm CYA is really, really high - in terms of active chlorine it is equivalent to about 50ppm FC at 60ppm CYA - SLAM level would be 24ppm.

That's why your swimming gear doesn't last long in public pools.