Differences Between Pool Calculator and Pool School

[crustfan]

pool-school/chlorine_cya_chart_shock

If I plug in the values from the SWG chart from above, I get different numbers in the suggested FC blue section for shock and SWG target. For instance, at 60 CYA, it reads 3 and 18 whereas the table reads 4 and 16. When I mouse over the 3 it confirms SWG FC Target 3 when it should be 4. Maybe it's supposed to say min target in the calculator?

Also what does Normal mean. The range for a 60 CYA from 5-9 seems way too high for a SWG.

 

[Bama Rambler]

The chlorine/cya chart is a little more aggressive than the Pool Calc but they both get the job done.

Normal is for normally chlorinated pools. If you have a swg you should use the swg number.

 

[chem geek]

The SWG level in The Pool Calculator is the same as the Minimum level in the Pool School chart. The Normal range low end is the same as the Minimum in the Pool School while the high end isn't in the Pool School chart. It is the Shock level that deviates from the Pool School chart the most where the Pool School chart is more aggressive. For shocking, there isn't a magic single level -- the higher the chlorine level, the faster chlorine will work. On the other hand, the minimum chlorine level (Normal for manual dosing; SWG when using a saltwater chlorine generator) is more of an absolute in that it is the level of chlorine needed to kill green algae faster than it can reproduce under almost all circumstances (i.e. regardless of algae nutrient level).

 

[crustfan]

So I'll ignore "Normal" since I have a SWG. Since I set my primary source of chlorine as SWG, shouldn't the program remove the normal from view? It does seem like the way it's programmed that those fields need to be static. An explanation in the Suggested FC Levels notes would help to understand.

Also, in those notes it says "The target FC level is a minimum." In the CYA chart there are two different columns one for Min and one for Target. Is the target the min or as I would think the target is someplace between the min and max. When I hover over the SWG value, the text says it's the target when in fact it's the min.

Also the Jug size drop down box seems to have no function in the application.

 

[chem geek]

I agree that the SWG numbers are showing the minimum. In practice, that's what most people use as a target since an SWG usually keeps the FC level fairly stable if it is run mostly during the day. One might argue that a Target number for the SWG isn't needed in the pool school chart (though some might use the higher FC in the Target column for extra safety against varying demand or anything going wrong) and that the text in The Pool Calculator hover-help should call the SWG number a minimum. As for automatically changing what is shown based on the "Primary source of chlorine" type, that would be nice, but after Jason sold The Pool Calculator to pSIFlow Technology, there have been minimal or no changes to it. Same with the iPhone app.