Pool Math Question

[eqbob]

In Pool Math, what's the assumed/background calculation number for the percentage of cyanuric acid in the liquid stabilizer? The natural chemistry stabilizer I get is equivalent to 30% CYA and was just wondering what pool math is using since there's no adjustment or drop down for different strengths, like there is for bleach.

This is merely a curiosity question not any kind of indictment! I love pool math!

 

[chem geek]

1 fluid ounce of liquid stabilizer is assumed to be equivalent to 0.387 ounces weight of CYA. Or put another way, one gallon increases CYA by 37 ppm. That is apparently incorrect and should be 32 ppm CYA so PoolMath needs to be changed. Based on the dosing instructions of the product, one gallon should raise the CYA by 32 ppm so one gallon should be equivalent to 42.73 ounces weight of pure CYA so one fluid ounce should be equivalent to 0.334 ounces weight of CYA.

There is only one liquid CYA product so no need for a pulldown, but a correction needs to be made in PoolMath. The "2890" in the following two pieces of code in PoolMath needs to be changed to "2500":

function CalcCYA()
{
var temp;

if (parseInt(document.F.CYAfrom.value) < parseInt(document.F.CYAto.value)) {
// Stabilizer
temp=(parseInt(document.F.CYAto.value)-
parseInt(document.F.CYAfrom.value)) *
GetGallons() / 7489.51;
document.F.CYA1oz.value=PutWeight(temp);
document.F.CYA1vol.value=PutVolume(temp * 1.042);
temp=(parseInt(document.F.CYAto.value)-
parseInt(document.F.CYAfrom.value)) *
GetGallons() / 2890;
document.F.CYA2oz.value=PutVolume(temp);
document.F.CYApcnt.value="some";
}
else {
document.F.CYA1oz.value=document.F.CYA1vol.value=
document.F.CYA2oz.value=0;
if (parseInt(document.F.CYAfrom.value) >
parseInt(document.F.CYAto.value)) document.F.CYApcnt.value=
Math.floor(100-(parseInt(document.F.CYAto.value)/
parseInt(document.F.CYAfrom.value))*100+0.5) + "%";
else document.F.CYApcnt.value="some";
}
}

:
case 25: // liquid stabilizer
result="raise CYA by "+Format(oz / GetGallons() * 2890);
break;

This should be tested (I didn't try it, but I think it would be correct).

 

[eqbob]

Thanks Richard. I always wondered why my results were slightly off from PoolMath using liquid stabilizer. I assumed it was always just me reading the test incorrectly. And I'm sure that's most of it, but a calc error could account for a bit of discrepancy as well.

I didn't know there was only one liquid CYA product. I much prefer that approach over the solid/powder.