Wk 2 Start Up CYA rising W/O Ever Adding Any ?

[parkinsmith]

CYA question! I am on week two of pool start up NEVER added any CYA but now my CYA is 45. Curoius what would cause a CYA to rise on its own without ever adding any in a new pool start up?

Yesterday CYA was 45,( up from 20 ), FC 5.5 , TA 100 , PH 7.8. (day beofre CYA was 40, CH 7.) PB put tabs in chlorinator (Until we add salt), said they were 99% Chlorine and did not have stabilizer in them. I just want to make sure it does not keep creeping up, get high and out of range becuase of something I am doing or that is off. I am testing with te Taykor K-2006 daily. Thanks

 

[Texas Splash]

PB put tabs in chlorinator (Until we add salt), said they were 99% Chlorine and did not have stabilizer in them.

That sounds like the problem right there. Tabs are stabilized which means their have a by-product in them - either stabilizer or calcium (cal-hypo). At start-up, either someone added stabilizer/conditioner, and/or those are trichlor tabs with stabilizer and each tab will add a few ppm of CYA. As long as tabs are in use, the CYA will increase.

Can you post a pic of the label from the tab bucket?

 

[HermanTX]

Since you have a SWCG, it is ok to let the CYA creep up but agree that you need to understand how that is happening. You want to refer to the FC/CYA Levels and click on the SWCG tab for recommended levels of CYA using a SWCG.

For a 15k gal pool, a fully dissolved 3” trichlor tab (8 oz.) will increase FC by 3.7ppm and raise CYA by 2.2ppm. So once you confirm what tabs are being used it would be helpful but fairly confident that since your CYA is increasing it is related to Trichlor tablets.

 

[parkinsmith]

That sounds like the problem right there. Tabs are stabilized which means their have a by-product in them - either stabilizer or calcium (cal-hypo). At start-up, either someone added stabilizer/conditioner, and/or those are trichlor tabs with stabilizer and each tab will add a few ppm of CYA. As long as tabs are in use, the CYA will increase.

Can you post a pic of the label from the tab bucket?

The PB left a bucket and NO LABLE on it . I did buy a bucket of my own asked for 99% I will go take a pic of that and post . ( have not used those yet ) I could swap out the tabs with mine . I have 2 weeks to go before adding salt and I do not want to get the CYA level too high. Any thoughts on how to do that ? I orginaly wanted to use liquid and asked PB but he just fired up the chlorinator.

 

[Toxophilite]

You might also want to revisit your testing of CYA. It takes some practice. That kit can't measure 45 CYA.

 

[parkinsmith]

That sounds like the problem right there. Tabs are stabilized which means their have a by-product in them - either stabilizer or calcium (cal-hypo). At start-up, either someone added stabilizer/conditioner, and/or those are trichlor tabs with stabilizer and each tab will add a few ppm of CYA. As long as tabs are in use, the CYA will increase.

Can you post a pic of the label from the tab bucket?

Here is the bucket I bought and HAVE NOT yet used. The tabs in there now are from PB and that bucket he left is not labled just a plain work bucket.

 

[parkinsmith]

You might also want to revisit your testing of CYA. It takes some practice. That kit can't measure 45 CYA.

The way I got that number is when I filled the tube with the cloudy mixture when the black dot went away the water was in between two numbers. I will re test and keep working at my testing I am just getting the hang of it

 

[Donldson]

I did buy a bucket of my own asked for 99%

That 99% means 99% pure trichlor. Trichlor is a chlorinated isocyanurate, meaning it is CYA and chlorine combined together. Your PB is mistaken and both his and your tablets will add CYA to the water.

 

[Bperry]

The buckets do say “stabilized” on them so you can be sure that there’s stabilizer in them.

 

[parkinsmith]

Since you have a SWCG, it is ok to let the CYA creep up but agree that you need to understand how that is happening. You want to refer to the FC/CYA Levels and click on the SWCG tab for recommended levels of CYA using a SWCG.

For a 15k gal pool, a fully dissolved 3” trichlor tab (8 oz.) will increase FC by 3.7ppm and raise CYA by 2.2ppm. So once you confirm what tabs are being used it would be helpful but fairly confident that since your CYA is increasing it is related to Trichlor tablets.

When I look at the FC/CYA chart now I should be looking at the chart for the chlorine pool as the SWG wont come on for another two weeks when I can add salt to the pool ? I have another 2 weeks so how can I keep the CYA down using the tabs? Keep the chlorinator on a very low setting ? Switch to liquid ?

 

[Hootz]

You want your cya to be around 70 for use with a swg. Continue using the tabs until you reach that stabilizer level and then switch to liquid chlorine.

The Free Chlorine and Cyanuric Acid Relationship

Managing your cyanuric acid and Free Chlorine levels is key to stabilizing your pool. Learn how these two items affect each other.

www.troublefreepool.com

 

[Getitrite]

The way I got that number is when I filled the tube with the cloudy mixture when the black dot went away the water was in between two numbers. I will re test and keep working at my testing I am just getting the hang of it

The CYA scale is logarithmic. Round UP. If between 45 and 50, use 50.

 

[tim5055]

I have another 2 weeks so how can I keep the CYA down using the tabs? Keep the chlorinator on a very low setting ? Switch to liquid ?

At this point I would shoot for 60 as your CYA. You can keep using tabs until then. But, you don't want to overshoot. Each tab you use in your pool is raisign the CYA by 2.2ppm so that tells you about how many tabs you can use.

As you have learned, there are no tabs that are pure chlorine. Consider what I'm about to say as learning.


In it's natural state, chlorine is a gas. Many large commercial pools actually use gas injection systems to chlorinate their pools.

Now, to change chlorine gas into something we can use at home it needs to be bound to something to turn it into a solid.

The "somethings" that are commonly used are -

• Stabilizer (also known as CYA)
• Calcium
• Lithium
• Water/lye

All of these add a little salt to your water, but they add something else. Cal-Hypo add calcium, Tri-Chlor and Di-Chlor (tabs and most granules) add stabilizer, Lithium hypochlorite adds lithium and liquid chlorine adds - water.

All of these things can be bad for your pool (except the water) in large quantities. The stabilizer helps shield the chlorine from UV degradation, but at higher levels it also impairs the ability of chlorine to do it's work. The higher the stabilizer level you have the higher the amount of chlorine you need. Too much calcium and you start to get scaling on the walls and floors of your pool.

 

[parkinsmith]

At this point I would shoot for 60 as your CYA. You can keep using tabs until then. But, you don't want to overshoot. Each tab you use in your pool is raisign the CYA by 2.2ppm so that tells you about how many tabs you can use.

As you have learned, there are no tabs that are pure chlorine. Consider what I'm about to say as learning.


In it's natural state, chlorine is a gas. Many large commercial pools actually use gas injection systems to chlorinate their pools.

Now, to change chlorine gas into something we can use at home it needs to be bound to something to turn it into a solid.

The "somethings" that are commonly used are -

• Stabilizer (also known as CYA)
• Calcium
• Lithium
• Water/lye

All of these add a little salt to your water, but they add something else. Cal-Hypo add calcium, Tri-Chlor and Di-Chlor (tabs and most granules) add stabilizer, Lithium hypochlorite adds lithium and liquid chlorine adds - water.

All of these things can be bad for your pool (except the water) in large quantities. The stabilizer helps shield the chlorine from UV degradation, but at higher levels it also impairs the ability of chlorine to do it's work. The higher the stabilizer level you have the higher the amount of chlorine you need. Too much calcium and you start to get scaling on the walls and floors of your pool.

Thank you this really helps my understanding of the process.

 

[Getitrite]

All of these add a little salt to your water, but they add something else. Cal-Hypo add calcium, Tri-Chlor and Di-Chlor (tabs and most granules) add stabilizer, Lithium hypochlorite adds lithium and liquid chlorine adds - water.

And... Salt ?

 

[tim5055]

And... Salt ?

Well, they all add salt - but I do stand corrected.....

 

[Getitrite]

My correction ... You led the sentence with "All of these add a little salt to your water". (I'm due for eye exam! )

 

[tim5055]

My correction ... You led the sentence with "All of these add a little salt to your water". (I'm due for eye exam! )

The more I participate in social media forum the more I need ot tell my self to slow down. Too poften I find myself reading for the point rather than reading for comprehension of everything written and overlook details. It happens to all of us.