Combined Chlorine

[rivermobster]

So along with the the Taylor test kit I bought, I have been using their app as well:

Check out "sureTREAT"
https://play.google.com/store/apps/details?id=com.taylortechnologies.suretreat

After doing a fresh refill of my pool, and getting everything all dialed in, the combined chlorine test is a bit out of range, the reading I have is 0.3, when the app calls for less than 0.2.

The app called for the addition of 13.6lb of Proteam Shock and Swim to eliminate this issue.

The question is...

What is the general consensus on this issue, and how would you eliminate it? And why?

Thanks in advance!

 

[JoyfulNoise]

We do not recommend the use of "guess"strips. They are far too inexact to be of any practical value and using a cell phone camera and app to attempt to "read" strips has been around for years now mostly with failure.

0.3ppm CCs is nothing, it's in the noise. 0.5ppm or less is perfectly acceptable. Pools can easily generate transient CC readings as high as 1 to 1.5ppm without requiring any intervention.

Chlorine and UV from the sun is more than adequate in dealing with CCs. Residential outdoor pools typically have such low bather loads that using a non-chlorine MPS based chemical like Shock & Swim is unnecessary. MPS can interfere with FC and CC measurements in the DPD and DPD-FAS tests and so one should be very careful before using those products. The only time MPS should be considered for use is with indoor pools that get no UV exposure and can build up CCs more quickly.

 

[MarianParoo]

You said in a previous thread that you have a K-2006. Are you also using test strips? I am a bit confused.

You have a top of the line kit with the 2006. Why don't you post a full set of results with that Taylor kit and then we can answer you with confidence and more specifically.

 

[rivermobster]

You said in a previous thread that you have a K-2006. Are you also using test strips? I am a bit confused.

You have a top of the line kit with the 2006. Why don't you post a full set of results with that Taylor kit and then we can answer you with confidence and more specifically.

Yeah, I'm not sure where the previous poster got the idea I'm using test strips. The result is from the k-2006 Combined Chlorine test.

Hope this screen shot works...

 

[pabeader]

I guess that's why we use Pool Math. You never know what those industry folks are trying to sell you.

 

[JoyfulNoise]

The sureTreat system you linked to is designed to work with test strips, although you can enter results manually. My apologies for assuming you used the strips but that is the primary purpose of the app - a test strip reader.

Either way, 0.3ppm CCs (how did you even measure that?) is still in the noise of CC measurements and does not require urgent treatment with MPS.

As in most cases with the pool industry, the app is designed primarily to get you to buy something you do not need.

 

[rivermobster]

The sureTreat system you linked to is designed to work with test strips, although you can enter results manually. My apologies for assuming you used the strips but that is the primary purpose of the app - a test strip reader.

Either way, 0.3ppm CCs (how did you even measure that?) is still in the noise of CC measurements and does not require urgent treatment with MPS.

As in most cases with the pool industry, the app is designed primarily to get you to buy something you do not need.

As I have stated twice now, I used the Taylor k-2006, and entered the results manually.

Here is the expanded view of their recommendations. FYI, Taylor does not sell any pool chemicals, they only sell the test kits...

 

[domct203]

I'm sure that Matt thought you were using guess strips as that is what that app was originally intended for:

"Just dip the strip, take a photo, and instantly receive a detailed test report with all you need to know for achieving balanced water."

It then goes on to mention that manual entry is also available.

Are you 100% certain that the apps recommended levels agree with TPFC? Using two different pool care programs at the same time is not recommended at all.

Is the app's FC recommendation based on the CYA level?

 

[domct203]

Either way, 0.3ppm CCs (how did you even measure that?) is still in the noise of CC measurements and does not require urgent treatment with MPS.

As in most cases with the pool industry, the app is designed primarily to get you to buy something you do not need.

As Matt mentioned, how did you get 0.3ppm? The CC test resolution is either by 0.2ppm or 0.5ppm.

You also need to decide if you want to follow TFPC guidelines or Taylor guidelines.

 

[rivermobster]

The "resolution" is based on how many drops you use, to get the color to change. So clearly, the "resolution" is not a fixed issue. It is a bit subjective.

It either case...

And still, original question remains...

What is the general consensus on Combined Chlorine, and how would you eliminate it? And why?

 

[jblizzle]

To make this easier ... stop using that app and just use PoolMath. Then we will all be on the same page.
Or use an app that at least follows the TFP recommendations.

CC is nothing to worry about unless it gets too high.
Have you read much of Pool School?
Read this: Pool School - ABCs of Pool Water Chemistry

 

[rivermobster]

To make this easier ... stop using that app and just use PoolMath. Then we will all be on the same page.
Or use an app that at least follows the TFP recommendations.

CC is nothing to worry about unless it gets too high.
Have you read much of Pool School?
Read this: Pool School - ABCs of Pool Water Chemistry

So now I see where you guys are getting the .5 number from. Anyone know where this info came from?

Poolcenter <---This article states .3

Taylor states .2

From the link you posted: In an outdoor pool, CC will normally stay at or near zero as long as you maintain an appropriate FC level and the pool gets some direct sunlight.

Seems like anything above 0 is a problem. But then again, even 0.5ppm is a pretty damm small number! lol

 

[rivermobster]

To make this easier ... stop using that app and just use PoolMath. Then we will all be on the same page.
Or use an app that at least follows the TFP recommendations.

CC is nothing to worry about unless it gets too high.
Have you read much of Pool School?
Read this: Pool School - ABCs of Pool Water Chemistry

I don't see a CC number here ---> http://www.troublefreepool.com/calc.html

Is there something I'm missing??

 

[domct203]

The "resolution" is based on how many drops you use, to get the color to change. So clearly, the "resolution" is not a fixed issue. It is a bit subjective.

When using a 25ML sample, each drop = 0.2ppm so the resolution of that test is 0.2ppm.

When using a 10ML sample, each drop = 0.5ppm so the resolution of that test is 0.5ppm.

Both are fixed values. If using the 25ML sample and it takes 2 drops to go completely clear, that is 0.4ppm.

It is how you are interpreting the test that is subjective. You are assuming that because it was "just a little pink" that the last drop somehow no longer counts as 0.2ppm.

- - - Updated - - -

I don't see a CC number here ---> http://www.troublefreepool.com/calc.html

Is there something I'm missing??

That is because we are not adjusting for CC. CC's are a byproduct.

 

[rivermobster]

Ok, this makes sense to me; rather than the CC being a solid number, it should be more of a calculation?

Chloramines combined chlorine problems in swimming pools

combined chlorine = total chlorine - free chlorine​

The combined chlorine value should never exceed 50% of the free chlorine value and should ideally be as close to zero as possible.

 

[domct203]

Ok, this makes sense to me; rather than the CC being a solid number, it should be more of a calculation?

Chloramines combined chlorine problems in swimming pools

combined chlorine = total chlorine - free chlorine​

The combined chlorine value should never exceed 50% of the free chlorine value and should ideally be as close to zero as possible.

CC should ideally be zero, but routinely 0.5ppm or less.

If your FC is 7ppm, you do not want a CC of 3.5ppm (50% of 7ppm FC), that's for sure.

 

[rivermobster]

That is because we are not adjusting for CC. CC's are a byproduct.

Indeed they are. Unless, you just recently refilled your pool, which I just did a couple of weekends ago...

https://www.epa.gov/dwreginfo/basic-information-about-chloramines-and-drinking-water-disinfection

- - - Updated - - -

CC should ideally be zero, but routinely 0.5ppm or less.

If your FC is 7ppm, you do not want a CC of 3.5ppm (50% of 7ppm FC), that's for sure.

I would agree! lol

 

[domct203]

Indeed they are. Unless, you just recently refilled your pool, which I just did a couple of weekends ago...

https://www.epa.gov/dwreginfo/basic-information-about-chloramines-and-drinking-water-disinfection

- - - Updated - - -



I would agree! lol

With proper sanitation & adequate sunlight, those CC's should burn off in no time.

 

[rivermobster]

With proper sanitation & adequate sunlight, those CC's should burn off in no time.

Now there is the question...

Do they burn off with sunlight??

From everything you read, you seem to need to shock hard to get rid of excessive CC. Or SLAM, as it's referred to on here. But then you read with an outdoor pool, they should stay at zero by themselves.

If the 50% rule applies...

Normal FC would be 3ppm. So the CC should be 1.5, clearly above what I have, do to my recent refill, and how the city treats the water. There would be no other explanation than that.

Correct?

 

[JoyfulNoise]

As I have stated twice now, I used the Taylor k-2006, and entered the results manually.

Here is the expanded view of their recommendations. FYI, Taylor does not sell any pool chemicals, they only sell the test kits...

If you wish to learn about combined chlorine in pools (not drinking water as in the EPA document you cite), the you can read these two posts -

Chloramines and FC/CYA

Chemistry of Chloramines - indoor commercial pool


Your initial post simply stated you had a Taylor test kit and your signature states "Taylor Technologies". There are many test kits and strips that Taylor markets to the pool world, so without a more precise statement, it would be hard for the reader to know exactly which kit you had. Combine that with you asking about an app that was primarily designed as a test strip reader, and I'm sure you can see how confusing your first post is.

As for the recommendations in that app, there is a lot of not-quite-right information there. If you wish to educate yourself on what the industry says versus what the truth is, you can read these threads -

Certified Pool Operator (CPO) training -- What is not taught

Breakpoint Chlorination

Yes, you are correct that Taylor sells test kits and not chemicals, but Taylor is also a major player in the pool chemical industry. DuPont is the maker of Oxone™ (MPS) which is both heavily marketed to pool chemical manufacturers like ProTeam as well as supported by Taylor through it's MPS interference removal test reagents. Historically speaking, DuPont was a major driving force in pushing MPS as a pool sanitizer and oxidizer (for obvious profit motive reasons) so it is not entirely shocking that an industry leader in pool testing would create a limit for a combined chlorine waste that would necessitate the use of a non-chlorine based shock. However, if you read the articles I suggested at the top of this post, you will see that 0.3ppm CC is nothing to worry about and that chlorine along with UV in sunlight is more than effective enough to destroy CCs without having to resort to using an expensive chemical like MPS. Given the transient nature of CC production in a low bather load residential pool, you will waste more time and money trying to measure and treat CCs than to simply focus on proper FC levels and simply track CCs as an indicator. Even on a fresh fill with treated municipal water that contains CCs (my fill water has 1ppm monochloramine in it for long-term secondary disinfection from our municipal supplier), the CC's will be rapidly destroyed within a day or two after proper FC levels are obtained.