Calculate TA and Ph with high CYA and FC

[FoolOfATook]

Hey all! Been on a bit of a journey with our pool (not the homeowner, roommate) and am seeking some targeted advice. For background, pool pump was out of commission for at least 2 months during the early part of the year and we had a bunch of storms, way too many pucks in floater that whole time (like 5-6), obviously huge algae bloom and pool was green. Cut to me taking over early this month using the TFP way (recommended by an uncle who is long term user) and pool is now super clear and looking great!! Performed OCLT and lost about 1ppm (tested around 8am, not 6am like I meant to) with no CC so we are good there.

For levels we are talking CYA of around 130-150. yes, seriously. Due to not having proper test kit, i went to pool store every day for about 2 weeks, plus a few days following that, then took an average of all CYA values given (from 93ppm all the way up to 161ppm) and am using a current value of 140ppm in PoolMath. It’s not an option for us to drain and refill due to drought restrictions/weather/etc.

To SLAM for the algae, we used liquid chlorine and had to bring our FC into the 30s+ and our current swim target is around 15/16ppm.

My questions are: is there a way I can accurately test my pH with such high FC? At the moment my kit is reading it as 8.2+, however the other day we accidentally fell below 10ppm and the water pH tested at like 7.5 on that day. Should I run with that as the accurate test? Is there a value/multiplier I can use to account or different method (using half pool water/half distilled) to get an accurate result?
Also, I have heard that CYA affects TA readings- is there a way I can adjust my home test results to get an accurate result? My home test put me at 110, whereas most recent pool store test (which says they adjust TA based on CYA) has me 79.

Our other roommate has planned a surprise party and needs the pool to be swimmable by August 4th so I want to make sure I’m able to get accurate FC, CC, pH, and TA results for swimmer safety.

I have attached before and after photos of the pool (we have staining on the surface) as proof of the TFP way!! Also, please feel free to ask me all the questions, I have graphs I made up and keep a log of all home and pool store test results

 

[jimbethesda]

Hey all! Been on a bit of a journey with our pool (not the homeowner, roommate) and am seeking some targeted advice. For background, pool pump was out of commission for at least 2 months during the early part of the year and we had a bunch of storms, way too many pucks in floater that whole time (like 5-6), obviously huge algae bloom and pool was green. Cut to me taking over early this month using the TFP way (recommended by an uncle who is long term user) and pool is now super clear and looking great!! Performed OCLT and lost about 1ppm (tested around 8am, not 6am like I meant to) with no CC so we are good there.

For levels we are talking CYA of around 130-150. yes, seriously. Due to not having proper test kit, i went to pool store every day for about 2 weeks, plus a few days following that, then took an average of all CYA values given (from 93ppm all the way up to 161ppm) and am using a current value of 140ppm in PoolMath. It’s not an option for us to drain and refill due to drought restrictions/weather/etc.

To SLAM for the algae, we used liquid chlorine and had to bring our FC into the 30s+ and our current swim target is around 15/16ppm.

My questions are: is there a way I can accurately test my pH with such high FC? At the moment my kit is reading it as 8.2+, however the other day we accidentally fell below 10ppm and the water pH tested at like 7.5 on that day. Should I run with that as the accurate test? Is there a value/multiplier I can use to account or different method (using half pool water/half distilled) to get an accurate result?
Also, I have heard that CYA affects TA readings- is there a way I can adjust my home test results to get an accurate result? My home test put me at 110, whereas most recent pool store test (which says they adjust TA based on CYA) has me 79.

Our other roommate has planned a surprise party and needs the pool to be swimmable by August 4th so I want to make sure I’m able to get accurate FC, CC, pH, and TA results for swimmer safety.

I have attached before and after photos of the pool (we have staining on the surface) as proof of the TFP way!! Also, please feel free to ask me all the questions, I have graphs I made up and keep a log of all home and pool store test results

You can get an electronic PH meter. I have the Apera Instruments PH60 and find it very helpful.

 

[jesse-99]

Yep, ditto on the pH60 from Apera. If your FC is really high, you can still measure with the digital, but won't be able to with the drop tests. Drop tests work great for almost all other circumstances.

 

[Bperry]

Hey all! Been on a bit of a journey with our pool (not the homeowner, roommate) and am seeking some targeted advice. For background, pool pump was out of commission for at least 2 months during the early part of the year and we had a bunch of storms, way too many pucks in floater that whole time (like 5-6), obviously huge algae bloom and pool was green. Cut to me taking over early this month using the TFP way (recommended by an uncle who is long term user) and pool is now super clear and looking great!! Performed OCLT and lost about 1ppm (tested around 8am, not 6am like I meant to) with no CC so we are good there.

For levels we are talking CYA of around 130-150. yes, seriously. Due to not having proper test kit, i went to pool store every day for about 2 weeks, plus a few days following that, then took an average of all CYA values given (from 93ppm all the way up to 161ppm) and am using a current value of 140ppm in PoolMath. It’s not an option for us to drain and refill due to drought restrictions/weather/etc.

To SLAM for the algae, we used liquid chlorine and had to bring our FC into the 30s+ and our current swim target is around 15/16ppm.

My questions are: is there a way I can accurately test my pH with such high FC? At the moment my kit is reading it as 8.2+, however the other day we accidentally fell below 10ppm and the water pH tested at like 7.5 on that day. Should I run with that as the accurate test? Is there a value/multiplier I can use to account or different method (using half pool water/half distilled) to get an accurate result?
Also, I have heard that CYA affects TA readings- is there a way I can adjust my home test results to get an accurate result? My home test put me at 110, whereas most recent pool store test (which says they adjust TA based on CYA) has me 79.

Our other roommate has planned a surprise party and needs the pool to be swimmable by August 4th so I want to make sure I’m able to get accurate FC, CC, pH, and TA results for swimmer safety.

I have attached before and after photos of the pool (we have staining on the surface) as proof of the TFP way!! Also, please feel free to ask me all the questions, I have graphs I made up and keep a log of all home and pool store test results

You can’t do much without the proper test kit. Don’t do anything based on average pool store test results. You will get burned if you do.

 

[mgtfp]

You can make a 1:1 dilution of a pool water sample with distilled water and do the pH test with that.

Since distilled water (this is important, you can't use tap water) has no FC and pretty much no TA, it will halve the chlorine so it doesn't interfere with the pH test anymore (assuming the original pool water FC was not higher than about 20ppm), but because your pool water is buffered it will not change the pH significantly.

This assumes that you are using the Taylor (or TFtestkits) pH test (R-0004 or R-0014), which has a special formulation so it works up to FC around 10ppm. Other phenol red pH tests will show chlorine interference mich earlier, so the dilution method would not cut the mustard.

Get a kit and stay out of the shop.

Edit: Sounds that you have one to test TA and I assume FC. Why don't you use that to test CYA?

 

[mgtfp]

Also, I have heard that CYA affects TA readings- is there a way I can adjust my home test results to get an accurate result?

TA is TA, it doesn't need correction. There is a huge confusion created by the pool industry.



Yes, CYA contributes to TA, but this contribution is real Alkalinity. All Alkalinity contributions are relevant for buffering against pH-drop.

TA is also used to estimate the amount of Carbonates in the water to calculate the saturation with Calcium Carbonate, to know if the water is at risk of creating scaling, or corrosive to plaster surfaces. To do that, the CYA contribution to TA (and the Borate contribution should Borates be present, but most pool stores won't even test for that) needs to be subtracted to get Carbonate Alkalinity, which can than be used to calculate the saturation index.

This is the only purpose of the correction, it should be done by the store's software internally without reporting the value back to the customer, it just creates confusion. And helps the pool store to sell more overpriced baking soda by making Alkalinity look lower, and force you into an expensive and tedious Muriatic Acid / Baking Soda see saw.

When using PoolMath, it will expect real totally Total Alkalinity values to be input, that have not been tampered with, as tested with the Taylor drop test. It does the correction internally in its formula to calculate the Calcium Carbonate (aka Calcite) Saturation Index (CSI).

 

[FoolOfATook]

You can make a 1:1 dilution of a pool water sample with distilled water and do the pH test with that.

Since distilled water (this is important, you can't use tap water) has no FC and pretty much no TA, it will halve the chlorine so it doesn't interfere with the pH test anymore (assuming the original pool water FC was not higher than about 20ppm), but because your pool water is buffered it will not change the pH significantly.

This assumes that you are using the Taylor (or TFtestkits) pH test (R-0004 or R-0014), which has a special formulation so it works up to FC around 10ppm. Other phenol red pH tests will show chlorine interference mich earlier, so the dilution method would not cut the mustard.

Get a kit and stay out of the shop.

Edit: Sounds that you have one to test TA and I assume FC. Why don't you use that to test CYA?

Correct- I have 2 separate kits, a Leslie’s kit that does pH, Alkalinity, and FC/bromines (homeowner bought this kit when he was the one in charge of pool care). Phenol red used for pH in that kit is R-0014. When I took over the pool care and realized our FC levels were going to need to be very high for slamming we got the basic Taylor FAS-DPD only kit, so, as first time novices who at that point hadn’t been as educated by TFP, we managed to not get a kit that has a CYA test and are not at the moment able to shell out for a whole new test kit, hopefully soon. So atm we are having to rely on pool store to get a value for CYA at all, which is why I chose the averaging approach, as there is literally no physical way we achieved that fluctuation in CYA over a period of less that 3 weeks with no draining.

 

[Bperry]

Correct- I have 2 separate kits, a Leslie’s kit that does pH, Alkalinity, and FC/bromines (homeowner bought this kit when he was the one in charge of pool care). Phenol red used for pH in that kit is R-0014. When I took over the pool care and realized our FC levels were going to need to be very high for slamming we got the basic Taylor FAS-DPD only kit, so, as first time novices who at that point hadn’t been as educated by TFP, we managed to not get a kit that has a CYA test and are not at the moment able to shell out for a whole new test kit, hopefully soon. So atm we are having to rely on pool store to get a value for CYA at all, which is why I chose the averaging approach, as there is literally no physical way we achieved that fluctuation in CYA over a period of less that 3 weeks with no draining.

I get it, but the pool store seems to get CYA test the most wrong more than all the other wrong tests they do. I had a CYA test kit earlier where you had to crush a tablet in the sample. Not sure how those work though.

 

[Mdragger88]

Cyanuric Acid (CYA) Test Kit

tftestkits.net

Gas is around $4 a gallon so this $21 kit will pay for itself after a few saved trips to the pool store.