Time to shock again?

[rpampt]

With CYA at 40, the normal FC range is 3 to 7, and never below 3. That doesn't mean you will need to go all the way up to 7 in order to keep FC at at least 3 the next day. Usually the level you need to aim for is lower than 7. In practice, when things are working well, you will tend to need to add about 2 ppm of chlorine each day, not 5.

Just went back and read this again. Maybe I'll start at my numbers listed before, then work it down to these numbers after I get a good idea of daily usage.

BTW, I understand it takes more chlorine to raise the level higher, but does maintaining the chlorine level higher use more chlorine once you have it elevated? Does having it too high cause any issues?

Thanks again!

 

[chem geek]

There is greater loss from sunlight from higher FC levels AT THE SAME CYA LEVEL, but if the higher FC levels are in proportion to the CYA level such that the FC/CYA ratio is roughly the same, then the higher FC (and CYA) levels have a lower loss of chlorine from sunlight.

When one is shocking, this usually means there will be more chlorine loss from sunlight, but then again one is shocking for a reason. When one is not shocking and instead maintaining a normal FC/CYA ratio as indicated in the Chlorine / CYA Chart, then higher FC and CYA levels (in proportion as shown in the chart) will result in lower absolute chlorine loss.