I'm bumping this to the top once more. I am really interested in a definitive answer. Not doubting waterbear....I think he's right..... but I am hoping some of you FG owners can confirm.

If FG is not suceptible to Cl damage, It would seem to make sense to advise much higher levels when shocking a gunite or FG pool.

I constantly see posts from algae-ridden users who "tip-toe" up to shock level and, because the FC starts to drop the minute they add the dosage, they never obtain shock (breakpoint)....prolonging their agony.

Am I correct in assuming that suggested shock levels for FG or gunite pools could safely be raised say to 50% higher levels than we currently suggest for vinyl pools?