Just trying the iPhone program. Took measurements: FC:1, pH: 7.6, TA:100, CH:200, CYA:0, CSI:-.22, Temp:62. Pool 16,400 gallon was just plastered and filled. trying to keep pH low 7.0 - 7.2 during cure. Using PoolMath it tells me to add 58 oz of 31.45% Muriatic acid to drop the pH. Taylor Reagents and resulted in Acid demand test of 1 drop. From Tables in the Taylor Pool spa test kit, they only suggest 15 oz (extrapolated from 10000 and 20000 gallon pool sizes). Why the large discrepancy? Am I doing something wrong?
Acid Demand
- Thread starter sts
- Start date
- Jun 22, 2014
- 47,885
- Pool Size
- 17888
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45 Plus
Welcome to TFP! 
Curious, what reference required you to drive the pH so low during cure? Was it your builder? You might like to see our TFP Start-up New Plaster - Trouble Free Pool page. Generally, we recommend keeping the over CSI (comprised of pH, TA, CH, and water temp) to about neutral or even slight above for the first 30 days. Now if your contractor required something different, you would follow their advice for warranty issues. But we would be curious.
For all dosing, we use the PoolMath tool and/or Poolmath app PoolMath - Trouble Free Pool. Check those out and let us know how we can help. We certainly want your new plaster to cure at its best.
Curious, what reference required you to drive the pH so low during cure? Was it your builder? You might like to see our TFP Start-up New Plaster - Trouble Free Pool page. Generally, we recommend keeping the over CSI (comprised of pH, TA, CH, and water temp) to about neutral or even slight above for the first 30 days. Now if your contractor required something different, you would follow their advice for warranty issues. But we would be curious.For all dosing, we use the PoolMath tool and/or Poolmath app PoolMath - Trouble Free Pool. Check those out and let us know how we can help. We certainly want your new plaster to cure at its best.
I might be wrong about this but figured I would at least try to help out. I attached the chart I believe you are using (via a quick Google search).
Pool Math is calculating for you to go from 7.6 to 7.0, correct? If so, the 15 oz. (from Taylor) must be to lower the pH by .1 (thus putting you from 7.6 to 7.5) So to go from 7.6 to 7.0, would take approximately 90 oz of 31.45 Muriatic Acid according to Taylor. If only going from 7.6 to 7.2 then the 58 oz suggested by Pool Math would be very close to Taylors recommendation of 60 oz (15 oz x 4 to reach 7.2 from 7.6).
Another difference that I don't think that Taylor takes into consideration is the TA level, because once you start changing that inside the Pool Math app, you will notice the difference of the amount of Muriatic Acid it takes to reduce the pH.
Pool Math is calculating for you to go from 7.6 to 7.0, correct? If so, the 15 oz. (from Taylor) must be to lower the pH by .1 (thus putting you from 7.6 to 7.5) So to go from 7.6 to 7.0, would take approximately 90 oz of 31.45 Muriatic Acid according to Taylor. If only going from 7.6 to 7.2 then the 58 oz suggested by Pool Math would be very close to Taylors recommendation of 60 oz (15 oz x 4 to reach 7.2 from 7.6).
Another difference that I don't think that Taylor takes into consideration is the TA level, because once you start changing that inside the Pool Math app, you will notice the difference of the amount of Muriatic Acid it takes to reduce the pH.
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Welcome to TFP!
For all dosing, we use the PoolMath tool and/or Poolmath app PoolMath - Trouble Free Pool. Check those out and let us know how we can help. We certainly want your new plaster to cure at its best.
The 7.0-7.2 is a requirement of the Builder, Anthony Sylvan. For first 14 days they want that pH, CH 150-200, TA:60-120, CYA: 0-30.
That is the correct chart. But I believe you are mistaken. The Chart gives what Taylor believes is the total amount of Muriatic Acid to add based on the Acid demand Test. In the test Phenol Red is used to indicate pH value based on color. The Acid Demand Reagent is added dropwise until the pH color meets the desired level. In this case, it only took one drop for pH to go from 7.6 to 7.0. Earlier tests took as many as 6 drops. It doesn't look at pH or TA directly, but you are actually titrating to the correct level for the pH and TA of the sample.
I checked myself using the acid demand chart and adding the ml for 15,000, 1000, and 400 gallons. Converted back to imperial, it's 15.8 oz. Close enough to your 15. Doublechecking with poolmath, it does indeed ask for 58 ounces.
I've never seen that much discrepancy before.
One thing I can think of is that the test kit is new and you have static electricity buildup on the R-009. That makes the drops smaller, so you need more, which gives a falsely high TA reading. And that will give a falsely high acid demand The other is a simple math error, using 25 ml factor and a 10 ml sample and getting a TA that is 250% higher than actual.
Repeat the TA test and wipe the dropper tip with a damp paper towel between drops. And make sure you multiply by the right factor.
If things still don't align, use the lesser dose and recheck it in an hour and see if it was enough.
I've never seen that much discrepancy before.
One thing I can think of is that the test kit is new and you have static electricity buildup on the R-009. That makes the drops smaller, so you need more, which gives a falsely high TA reading. And that will give a falsely high acid demand The other is a simple math error, using 25 ml factor and a 10 ml sample and getting a TA that is 250% higher than actual.
Repeat the TA test and wipe the dropper tip with a damp paper towel between drops. And make sure you multiply by the right factor.
If things still don't align, use the lesser dose and recheck it in an hour and see if it was enough.
Retested with similar results. Checked with test strips as well. I added the 15 oz. of acid. I will check on the effect tomorrow. Maybe Taylor is just very conservative with the additions. Thanks for the help.