Cyanuric Acid problem

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K9waves said:
2:00 Today Test
CYA 40
ph 7.2
TA 120
Calcium 310
DPD -- Free Chlorine .4
Combined Chlorine .6

Put 70 oz of liquid chlorine in pool

7:00 p.m. went back to check #'s
Chlorine sky high
Couldn't get a number because I stopped adding drops after I added 80 and still sample was bright pink.

No change in water cloudiness.

Made the mistake of doing this the day before we are scheduled to work. Will have to go in early and try to neutralize the chlorine if it hasn't come down.
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Why did you add 70oz? You only needed 1/2 of that at the most. If you use the PoolMath app, it’ll help avoid making that mistake again as it calculates how much to add depending on the current level

The DPD test doesn’t go above 10ppm. (Or 5ppm, I forget). If you get the FAS-DPD it reads a lot higher than you’ll ever need.
 
So let's address some things from your last post:
1. No need to wait 2 hours after adding chlorine. If you wish to follow various online services that's your purgative, but you can't mix & match those online recommendations or local pool store services with this forum. You'll go nuts. Realistically, there is absolutely no reason to wait two hours for chlorine to mix.
2. 70 ounces of 10% chlorine in a 4,500 gal pool increases the FC from zero to 12. Since your current CYA seems to be 40, you are not even at SLAM level yet (see the FC/CYA Levels), and you can swim in a pool at SLAM level. Realistically you could be in the water with the FC at 16 right now if you wanted to.
3. There is no need to neutralize the chlorine. To the opposite, based on what's been happening the past couple days, next to now recorded FC level and cloudy water, your water needs to be at or close to SLAM level.
4. Based on your chlorine (DPD) test note above, I have a concern about the accuracy of your FC testing. To confirm, you should be doing it as follows:

Using the FAS-DPD (powder & drops), you should be using a 10 ML water sample size, then adding one generous scoop of R-0870 powder. Mix and add drops of R-0871 until clear then divide answer in half. Example: 24 drops equals an FC of 12.
 
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Texas Splash said:
So let's address some things from your last post:
1. No need to wait 2 hours after adding chlorine. If you wish to follow various online services that's your purgative, but you can't mix & match those online recommendations or local pool store services with this forum. You'll go nuts. Realistically, there is absolutely no reason to wait two hours for chlorine to mix.
2. 70 ounces of 10% chlorine in a 4,500 gal pool increases the FC from zero to 12. Since your current CYA seems to be 40, you are not even at SLAM level yet (see the FC/CYA Levels), and you can swim in a pool at SLAM level. Realistically you could be in the water with the FC at 16 right now if you wanted to.
3. There is no need to neutralize the chlorine. To the opposite, based on what's been happening the past couple days, next to now recorded FC level and cloudy water, your water needs to be at or close to SLAM level.
4. Based on your chlorine (DPD) test note above, I have a concern about the accuracy of your FC testing. To confirm, you should be doing it as follows:

Using the FAS-DPD (powder & drops), you should be using a 10 ML water sample size, then adding one generous scoop of R-0870 powder. Mix and add drops of R-0871 until clear then divide answer in half. Example: 24 drops equals an FC of 12.
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First -- Thanks for putting up with me.
I am grateful to have found this site. I believe I'm getting the best info here. I have gotten poor information from the pool store and my testing never matches their results. I have a pool guy who is good with mechanical issues.

It's a relief I don't have to wait hours after adding the liquid chlorine.

You are correct, I am not sure I did the FAS-DPD test correctly. I followed the Taylor instructions and they were a bit confusing.
Your formula was easier and it makes more sense to use the 10 ml tube.

This morning I followed your test instructions and the result was 10 fc. Water was still cloudy and water did feel a bit harsh on my skin.

Tomorrow after we close, I will do another SLAM.

Thank you!
 
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Glad to hear you feel more comfortable with the FC testing. :goodjob: Since you mentioned the SLAM Process, I want to cover a couple things:
1 - The key of a successful SLAM is to maintain the appropriate/elevated FC level until all 3 criteria have passed. Based on your current CYA of 40 that would be an FC of 16. We get that number from the FC/CYA Levels.
2 - However, since the primary purpose of your pool is for dog rehabilitation, I would like to ask @JoyfulNoise if there are any special precautions we/you should know about when it comes to elevated chlorine levels for canines versus humans. Doesn't hurt to ask.
 
Texas Splash said:
Glad to hear you feel more comfortable with the FC testing. :goodjob: Since you mentioned the SLAM Process, I want to cover a couple things:
1 - The key of a successful SLAM is to maintain the appropriate/elevated FC level until all 3 criteria have passed. Based on your current CYA of 40 that would be an FC of 16. We get that number from the FC/CYA Levels.
2 - However, since the primary purpose of your pool is for dog rehabilitation, I would like to ask @JoyfulNoise if there are any special precautions we/you should know about when it comes to elevated chlorine levels for canines versus humans. Doesn't hurt to ask.
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Would appreciate any info regarding dogs. Most of the dogs are disabled or compromised. In the water they are able to be somewhat normal and can do things they can't do on land. I Want to make sure they are safe. They chase balls and toys so they do ingest water.
 
K9waves said:
Would appreciate any info regarding dogs. Most of the dogs are disabled or compromised. In the water they are able to be somewhat normal and can do things they can't do on land. I Want to make sure they are safe. They chase balls and toys so they do ingest water.
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My kids, 4 and 6, swim without goggles at FC levels above 10+ without issue.
Our dogs are in and out of the water, as well, so no issues there.

It was pointed out a few messages ago, but the key to SLAM is not to wait around until FC falls below the target level. It has to be maintained at or above that level, but the important aspect is that it’s 100% safe to swim and be in the water at those levels. So I encourage you to test and dose liquid chlorine throughout the day, as much as possible.

Also - a note for the group - isn’t CYA not allowed in indoor commercial pools? Also - the UV system would also be reducing FC, right, but I believe indoor pools it can be useful.
 
reggiehammond said:
My kids, 4 and 6, swim without goggles at FC levels above 10+ without issue.
Our dogs are in and out of the water, as well, so no issues there.

It was pointed out a few messages ago, but the key to SLAM is not to wait around until FC falls below the target level. It has to be maintained at or above that level, but the important aspect is that it’s 100% safe to swim and be in the water at those levels. So I encourage you to test and dose liquid chlorine throughout the day, as much as possible.

Also - a note for the group - isn’t CYA not allowed in indoor commercial pools? Also - the UV system would also be reducing FC, right, but I believe indoor pools it can be useful.
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Thankyou.
Yes, I wondered if my UV system could be contributing to lack of chlorine remaining in the water. I was using dichlor tablets and shock but CYA build up was giving me a lot of trouble.
 
A swg won’t clear up your current issue- it will just feed your pool adequate maintenance amounts of fc daily if sized properly & set to do so vs you manually dosing. Swg’s are fc maintainers.
Regardless of which method you choose to feed your pool for daily maintenance, the solution to the current condition is the SLAM Process with liquid chlorine.

The uv can oxidize some fc - it’s purpose is oxidizing bather waste (cc’s) but its a light bulb & cannot differentiate - it oxidizes whatever passes over it to its potential.
Uv oxidizing fc is most noticeable in pools/spas with low use when there’s no cc’s for it to eat.
The amount of bather waste in your pool has likely been overwhelming your current maintenance fc doses - the uv may or may not have been helping oxidize some of the bather waste - there’s really no way to know if that system is working or not. The answer is more chlorine, as it is both a sanitizer & an oxidizer. Uv is only an oxidizer.
You mentioned the water felt harsh with higher levels of fc - you did not mention your cc level. Elevated cc’s are quite harsh for skin & eyes, generally when u smell that “chlorine smell” or its burning your nose you are smelling cc’s.
The answer is more chlorine —> slam process until the cc’s are reduced to 0.5 or less. Along with the other end of slam criteria being met.
Ph that’s too low or too high can also cause irritation & make the water feel harsh.

The pool is safe/comfortable to swim in when -
*Cc’s are 0.5 or less
* fc is between minimum & slam level for your cya
* you can see the bottom of pool for safety purposes
* ph is in the 7’s
 

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Not to go off topic, but question- Why does CYA have to be so much higher while using a SWG as compared to not using one? I a
just ordered my first SWG and am trying to figure out the proper levels before it's installed. It doesn't make sense to me that having a CYA of 70 will be good for fc.
 
HSBigDaddy said:
Not to go off topic, but question- Why does CYA have to be so much higher while using a SWG as compared to not using one? I a
just ordered my first SWG and am trying to figure out the proper levels before it's installed. It doesn't make sense to me that having a CYA of 70 will be good for fc.
Click to expand...
As for why the higher cya is suggested:
A swg produces small amounts of fc over a long period of time to reach your desired target 🎯 the higher cya (chlorine sunscreen) protects it from being depleted by the sun as fast as it’s being produced.
This helps the swg maintain adequate fc levels at lower percentages/run times thus increasing the cell’s lifespan- as all swg cells have a finite life span (approx. 8-10k hrs @100%)
Why the allowed fc levels are lower for swg pools than manually chlorinated ones:
* Most saltwater chlorine generator (SWG) pools appear to prevent algae at a minimum FC level of 4.5% of the CYA level as compared with the roughly 7.5% of the CYA level shown in the "Min FC" column for manually dosed pools.
U can read more on that here 👇

Chlorine/CYA Chart

EDIT: You will find a simplified and standardized version of this chart at Pool School, Chlorine / CYA Chart. Chlorine/CYA Chart by Chemgeek FC = Free Chlorine in parts-per-million (ppm) CYA = Cyanuric Acid in parts-per-million (ppm) CYA ........... Min FC3 ..... Target FC ...... Yel/Mstrd...
www.troublefreepool.com www.troublefreepool.com
& here 👇

Pool Water Chemistry

This thread presents my findings so far on pool water chemistry including the following: More Accurate Calcite Saturation Index (CSI) to replace Langelier Saturation Index (LSI) Calculation of ppm HOCl (disinfecting chlorine) at various levels of Total Free Chlorine (FC) and Cyanuric Acid (CYA)...
www.troublefreepool.com www.troublefreepool.com
 
HSBigDaddy said:
Not to go off topic, but question- Why does CYA have to be so much higher while using a SWG as compared to not using one? I a
just ordered my first SWG and am trying to figure out the proper levels before it's installed. It doesn't make sense to me that having a CYA of 70 will be good for fc.
Click to expand...
It’s a suggestion, not a requirement. If your current level is ok with you then keep it there.

The suggestion is just that a higher level can help protect some more of the chlorine.
 
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Flying Tivo said:
I also have Dogs, i try to keep 2-3ppm higher than recommended in the FC/CYA Levels. This is the best advice for Dogs in pools i have gotten from TFP, you will love it. Use them on your skimmers basket.
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Thank you for info. Very funny.
 
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