Pool Math App - Strange Behaviour

[DT770]

Hello tfp community,

I noticed a strange issue when using the "effects of adding" function in the Pool Math App on Android. The app shows that there is no FC increase when entering bleach concentrations above 10%.
You can see this in the attached screenshots. Even a tiny decimal beyond 10% of 1L leads to a 0.5 FC increase. If I recall correctly, TFP's web page calculator does not exhibit the same result.

Anyone experienced the same?

Edit: Looks like thread got created in the wrong sub forum. Was on mobile and seemingly chose the right section.... Mods, please move this thread to where it fits best

 

[DrewLG]

Yeah, I see it too. It looks like all concentrations [0-5.25%] are treated the same, and higher concentrations are also grouped: (5.25-6%], (6-8.25%], (8.25-10%], and (10-100%] (and above). Weird.

 

[mknauss]

I think this was discussed before --
@Leebo
@redth

 

[DT770]

Yeah, I see it too. It looks like all concentrations [0-5.25%] are treated the same, and higher concentrations are also grouped: (5.25-6%], (6-8.25%], (8.25-10%], and (10-100%] (and above). Weird.

Exactly what I discerned as well, but didn't detail in my OP. The groupings are awkward when aiming for more refined control of chlorine levels. I wonder if any other calculations have similar behavior that is not evident at first glance?

 

[Krulligo]

I have also had issues with some weird behavior. Lets say I am looking at my pool chlorine and I say my current chlorine level is 5ppm and target chlorine is 7ppm. At the bottom it tells me how much bleach to add and then there is a "Log addtion..." button. When I click that, and then select "Suggested Amount", most of the time it logs a wrong amount than what was suggested. Sometimes the logged amount doesn't make sense, like gives me negative values.

 

[mknauss]

Whenever you see issues with the app, please email [email protected]. Screen shots of what you are seeing that is an issue really help.

 

[proavia]

In the pics the OP posted, the pool volume is in gallons and the chemical quantity added is in liters.
I wonder whether that might be leading to the issues mentioned.

 

[mknauss]

I did not catch that.

 

[DrewLG]

Great idea. But I got my results, same as the OP's, using gallons and ounces.

 

[DT770]

I use gallons for the pool volume because it is an approximate calculation and 12500 Gal is easier on the eyes than 47317.647 L
On a side note, if the app were to get an update that would show how much liquid chlorine is needed in LITRES that would be amazing!

Thanks for the testing @DrewLG

 

[mgtfp]

On a side note, if the app were to get an update that would show how much liquid chlorine is needed in LITRES that would be amazing!

If you want the additions metric, then you have to define your pool volume metric.

 

[mgtfp]

I can reproduce that behaviour. Above 10%, the effect of adding doesn't change when increasing the bleach percentage.

 

[DT770]

If you want the additions metric, then you have to define your pool volume metric.

Thanks for the awesome tip! I was getting annoyed having to convert oz. to l all the time...

@Leebo
@redth

 

[david_]

I have also had issues with some weird behavior. Lets say I am looking at my pool chlorine and I say my current chlorine level is 5ppm and target chlorine is 7ppm. At the bottom it tells me how much bleach to add and then there is a "Log addtion..." button. When I click that, and then select "Suggested Amount", most of the time it logs a wrong amount than what was suggested. Sometimes the logged amount doesn't make sense, like gives me negative values.

Ever find a solution to this? Same thing happens to me, inconsistently.

 

[DT770]

I haven't encountered a log issue like that yet, seems like it is quite frustrating to deal with.
As an update, the original issue is still present as of June 2023. Otherwise, using the app's home page calculators give correct results and even minute concentration changes are reflected.