Can You Maintain High CYA with High FC?

[polyharmonic]

I know that if your CYA is high, then you need to keep your FC high. On the chart, it says that:
CYA=100ppm
Minimum FC=8
Target FC=11-13
Shock FC=39

Is it that at CYA=100ppm, it is just not possible to reach those FC targets? I mean if I bought enough bleach wouldn't I be able to reach those FC targets? According to poolmath (unless I have it wrong), it says you just need 4 gallons of 10% bleach to reach Shock FC=39.

Okay let's say you reach your target FC with high CYA. Doesn't the CYA then minimize FC loss? So although you need to maintain a FC=13, once you reach it, why can't you maintain it?

Or is it that the higher the FC, the greater the loss and so it becomes much more expensive and difficult to maintain that high FC (which seems to contradict that high CYA would minimize FC loss).

 

[mknauss]

Certainly you can maintain it with additional bleach. At Target levels there will not be great burn off of chlorine due to UV. At shock, yes there will.

The biggest issue is not being able to test pH. Your pH test is invalid with FC above 10.

It is so much easier to just replace some water. In Phoenix you will need to do that every 2 years or so due to CH build up.

Take care.