TA value and CYA?

[a-castan]

I have a bit of a mess on my hands right now. Did the pool drain to get the CYA down... I got a ways to go. Got my chem test kit and still unsure if I'm getting it right. My estimation is ~ 100 but it might be wishful thinking or my power of focus on that dam dot. So took to the pool store to see if they get the same. They got 134, which is about the same they got on 3/27. OK, more draining needed in either case. But when I took my TA value I got 120ppm. They adjusted my TA value to 75 because of the CYA level. I'm afraid to ask, but what's the math behind that?

 

[Texas Splash]

There is a way to do an adjusted TA, but for us it's typically irrelevant and we just stick to the standard TF-100 or Taylor K-2006C results. But you can see more details about an adjusted TA in the link below.

Adjusted TA for CYA

Pool has been doing very well and testing is going well on my own. Today I had to run a sample to my Leslie’s store so I could get my CYA tested since I ran out of fluid and it’s been a while since I tested. They said my numbers were really good but said I needed to add 3lbs of Baking soda since...

www.troublefreepool.com

 

[JoyfulNoise]

You only need to adjust the TA value in order to calculate the saturation index (CSI or LSI) properly. TFP doesn’t make users calculate adjusted TA, the PoolMath App does it automatically. Just stop going to the poom store, it’s only going to confuse things

 

[a-castan]

OK, so makes sense... 1/3 of my CYA subtracted from the TA (134/3=45) - 120=75. So they want me to bring up the TA... and maybe I should, but seems to me that CYA level is causing all kinds of issues. Can't keep FC up, Ph hates me and threatens to go up... not sure what I should do first. They suggest 1) increase TA 2) add acid to lower PH and then 3) add 2 gallons CHL. I dont want to go without sanitizer certainly, but it sure seems to be just another trip around the block and back to a CYA issue. Think I'll shock tonight and then plan on another drain tomorrow... thoughts?
signed, trouble in texas

 

[a-castan]

You only need to adjust the TA value in order to calculate the saturation index (CSI or LSI) properly. TFP doesn’t make users calculate adjusted TA, the PoolMath App does it automatically. Just stop going to the poom store, it’s only going to confuse things

I downloaded the app, but I could not figure out where to start... and while I'm not a power user, I'm on a computer every day all day... I'll give it another shot...

 

[JoyfulNoise]

Ok. Stop listening to the pool store their advice is total . If you raise TA with their expensive baking soda and then add acid … you lower TA. So their advice results in nothing being achieved but lessening the amount of money in your wallet.

Focus on reducing CYA. That’s it. Keep adding a 1/2 gallon of LC per day until you get your CYA reduced.

 

[a-castan]

Thanks so much Joyful! It did seem like a circle to me.

 

[newdude]

My estimation is ~ 100 but it might be wishful thinking or my power of focus on that dam dot

First off, it's a googely eye. And that lousy no good laughing at you.......

anywho. Focus *IS* your issue. Take a flash of a glance. If you don't see it instantly, stop. If you stare, your brain will find it no matter what.

Wanna see your brain lie to you? Look at your nose. It's been there for a while, at least all week. But you haven't seen it until now.

So just a fast glance. Fill only to the 10s and call it when it's not there. Suck the juice back into the squirt bottle and get 2 out of 3 to agree. You can reuse it for as many tests as you need.

 

[mgtfp]

It's very annoying that pool stores do this correction and still call it "TA". It's not "Total" Alkalinity anymore once you subtract one type of Alkalinity from it. They should just do this subtraction internally within their software to calculate CSI, but there is no reason why this value should be passed on to the customer.

And then tell them that their TA is too low and sell them overpriced baking soda, because they apply the same limits (which are too high to start with) after they have already artificially reduced the TA value.

They make good (or should I say dirty?) money out of this scam by selling even more baking soda and muriatic acid to create an even bigger pH/TA seesaw.

 

[a-castan]

Hiya, and good morning! Hope peoples still with me to weigh in. @Texas Splash , hope to hear from you, or any folks with big sun. I'm in the San Antonio TX area, and I've seen so many ideals for CYA level thought I would ask. So confession... I am using the pool store's value for CYA since me and dot don't see eye to eye yet (nyuk nyuk).
I'm draining today - again - and if I take out what I did last time, I should get the CYA to 70.

Stats: FC= .68 TC= .93 TA=120 (my#) CH= 328 Ph-7.8 CYA= 134 (draining first, then balance)

Question: My pool gets the sun from 10am ish to 4pm ish - would 70 still be too high or should I go for 60?

Speaking of stats, I don't see mine under my profile pic... need to check settings. (14.5K gallon gunite/chlorine)
Question: If CYA is too high you'll have to maintain higher FC, but if too low I thought I read its the same issue?
Question: is gunite the same as plaster?
Thanks in advance people!!!

 

[ajw22]

Question: My pool gets the sun from 10am ish to 4pm ish - would 70 still be too high or should I go for 60?

If you a e chlorinating with Liquid Chlorine then target CYA 40-60.

Question: If CYA is too high you'll have to maintain higher FC, but if too low I thought I read its the same issue?

Follow the FC/CYA chart...

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

Question: is gunite the same as plaster?

No, gunite is the cement pool shell that the plaster is put on top of. If your pool is gunite then you have plaster on top of it. Gunite is not waterproof and no one has a pure gunite pool.

 

[a-castan]

If you a e chlorinating with Liquid Chlorine then target CYA 40-60.



Follow the FC/CYA chart...

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

No, gunite is the cement pool shell that the plaster is put on top of. If your pool is gunite then you have plaster on top of it. Gunite is not waterproof and no one has a pure gunite pool.

Thanks! That makes alot of sense, and you're right there is a shell of plaster, so I should call my pool style plaster when asked.

 

[a-castan]

And thanks for answering my other questions too... I did refer to the FC/CYA chart. It just seemed that I heard so many different values for ideal and max CYA.
I think the forum's pool school info says 40-50 ideal, 50-60 max... and then other people replying on threads had other numbers,.. AND of course the pool store says max 100... but they just want to sell chlorine, right?

I just finished draining, and this time I got as close to the equalizer drain as possible... really aiming at that 60!!!

 

[Texas Splash]

I'm just up FM-78 towards Marion a bit in the country. No shade around the pool. It gets full sun morning to dusk. You'll see later why testing your own CYA accurately and finding a good CYA level is so important. For now though, just focus on that water exchange and doing your own testing. The PoolMath APP is a great tool as well.

FYI - I converted to salt a couple years ago, but before that time my CYA was at about 50-60 this time of year. Very soon though, I had no problem going to 70, especially from Jun - Sep to save the chlorine from the TX sun. HOT!

 

[a-castan]

Thanks @Texas Splash ! I think my profile says it, but Schertz here. Nice to meet you! I did revisit the pool app and I'm sure I will be able to use it once I have data to add. And I will absolutely not give up on getting more accurate with the CYA test. I donated to become a forum member and got a nice discount on the Taylor Test kit. Of course I began practicing right away. And if I calculated right and get below 70 after this drain, I'll be happy. Considering it started over 200!! Thinking I might send my water bill to the pool service folks I was using up until March. But then I know this is all on me.
So slow... this will be a long day...

 

[ajw22]

. And I will absolutely not give up on getting more accurate with the CYA test.

CYA test does not need to be accurate. +/- 10 ppm is fine. Just round up.

The only reason we measure CYA is to set the FC level. Round up and you will always have sufficient FC following the FC/CYA Levels