Accuracy of volume estimate

[Biff Ditt]

PoolMath calculated that my volume is around 29,000, but I am not getting the estimated chemical responses based on PoolMath's recommended chemical dosages. Here is the most recent chemical addition data:

1) At 5:50pm the FC was 4.5 ppm.
2) 511 oz of 10% sodium hypochlorite bleach was added at 6:26pm
3) The FC was remeasured at 6:56pm and was found to be 15.5 ppm
Notes: The sun was not shining. The pump was circulating.

I fed this along with other data to some LLM's and they are spitting out that the volume is likely around 36,000 gallons. Does this seem correct?

Here is other recent data exported from PoolMath. All bleach was 10%. Muriatic acid was 31.45%
Build Type: Plaster
Volume: 28912 gallons
Chemistry: Liquid Chlorine
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Latest Test Result Summary:
FC: 15.5 (1 hour ago)
pH: 7.5 (1 hour ago)
TA: 70 (2 hours ago)
CH: 250 (2 hours ago)
CYA: 50 (1 hour ago)
TEMPERATURE: 74° (2 hours ago)
CSI: -0.43 (1 hour ago)
==========================================
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Test Results 06-04-2024 @ 07:06 PM
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CYA: 50
CSI: -0.43

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Test Results 06-04-2024 @ 06:59 PM
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pH: 7.5
CSI: -0.38

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Test Results 06-04-2024 @ 06:55 PM
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Free Chlorine: 15.5
CSI: -0.80

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Chemical Addition 06-04-2024 @ 06:50 PM
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+ 8 Pounds of CalciumChloride

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Chemical Addition 06-04-2024 @ 06:26 PM
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+ 511 FluidOunces of Bleach

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Chemical Addition 06-04-2024 @ 06:12 PM
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+ 46 Ounces of DryStabilizer

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Chemical Addition 06-04-2024 @ 06:04 PM
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+ 65 Ounces of Borax

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Test Results 06-04-2024 @ 05:50 PM
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Free Chlorine: 4.5
pH: 7.0
Total Alkalinity: 70
Calcium Hardness: 250
CYA: 33
Temperature: 74°F
CSI: -0.80

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Chemical Addition 06-03-2024 @ 05:43 PM
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+ 1 Gallons of Bleach

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Test Results 06-03-2024 @ 05:21 PM
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Free Chlorine: 6.5
pH: 7.2
Total Alkalinity: 70
Calcium Hardness: 250
CYA: 25
Temperature: 70°F
CSI: -0.67

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Test Results 06-03-2024 @ 07:31 AM
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Free Chlorine: 15.0
Calcium Hardness: 200
CSI: 0.16

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Chemical Addition 06-02-2024 @ 07:06 PM
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+ 327 FluidOunces of Bleach

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Chemical Addition 06-02-2024 @ 05:29 PM
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+ 8.6 Pounds of CalciumChloride

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Chemical Addition 06-02-2024 @ 05:19 PM
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+ 3 Gallons of Bleach

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Chemical Addition 06-02-2024 @ 05:02 PM
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+ 29 Ounces of DryAcid

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Chemical Addition 06-02-2024 @ 05:00 PM
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+ 133 Ounces of BakingSoda

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Chemical Addition 06-02-2024 @ 04:53 PM
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+ 171 Ounces of DryStabilizer

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Test Results 06-02-2024 @ 01:58 PM
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Free Chlorine: 0.0
pH: 8.2
Total Alkalinity: 50
Calcium Hardness: 150
CYA: 0
Temperature: 70°F
CSI: 0.04

 

[ajw22]

Your FC went up by 11ppm when adding 511 oz of 10% liquid chlorine.

PoolMath says:



Now if the potency of the liquid chlorine is 8% then...



What was the date code on the liquid chlorine? How as it stored from when it was manufactured to when it got in your pool?

I suspect your liquid chlorine was a bit weak.

Breakdown of Bleach Over Time by Storage Temp - Further Reading

www.troublefreepool.com

 

[GilesM]

What are your pool dimensions and average depth?

 

[Biff Ditt]

Your FC went up by 11ppm when adding 511 oz of 10% liquid chlorine.

PoolMath says:

View attachment 581471

Now if the potency of the liquid chlorine is 8% then...

View attachment 581472

What was the date code on the liquid chlorine? How as it stored from when it was manufactured to when it got in your pool?

I suspect your liquid chlorine was a bit weak.

Breakdown of Bleach Over Time by Storage Temp - Further Reading

www.troublefreepool.com

Your FC went up by 11ppm when adding 511 oz of 10% liquid chlorine.

PoolMath says:

View attachment 581471

Now if the potency of the liquid chlorine is 8% then...

View attachment 581472

What was the date code on the liquid chlorine? How as it stored from when it was manufactured to when it got in your pool?

I suspect your liquid chlorine was a bit weak.

Breakdown of Bleach Over Time by Storage Temp - Further Reading

www.troublefreepool.com

Your FC went up by 11ppm when adding 511 oz of 10% liquid chlorine.

PoolMath says:

View attachment 581471

Now if the potency of the liquid chlorine is 8% then...

View attachment 581472

What was the date code on the liquid chlorine? How as it stored from when it was manufactured to when it got in your pool?

I suspect your liquid chlorine was a bit weak.

Breakdown of Bleach Over Time by Storage Temp - Further Reading

www.troublefreepool.com

April 4th 2024. Pool Essentials Chlorinating Liquid. Bought at Walmart. Stored in the kind of indoor/outdoor space between the outdoor garden area and conditioned indoor space. Shielded from direct sunlight.

 

[Biff Ditt]

What are your pool dimensions and average depth?

Kidney shaped (ignoring the little circular entrance area---see attached)
Length:39ft
Width in shallow end: 18.66ft
Width in deep end: 16.83ft
Depths: Shallow--->Deep: 3.33'---4.5'---6'(middle)---8.83'----7.83'

 

[GilesM]

You are probably right around 28-29,000 gallons I guess. Kidney shaped pools are tough and yours is pretty deep.