when is it safe to swim after "shock"?

[kjmelak]

After noticing a few patches of algae growing on my liner (and there was heavy rainfall the past week), I decided to superclorinate.

Raised Free Chlorine to 15ppm (CYA is 50) at around 4:00PM. Question is, how long do I have to wait before it is safe to swim?

[KurtV]

KJ,
I don't think you'll get a definitive answer here. There's a fair amount of controversy on the topic of safe levels of chlorine in pools as evidenced by this thread: http://www.poolforum.com/pf2/showthread.php?t=3920.

[aylad]

I'd swim in it at about 7 or 8, wearing an old suit.....or at about 4 or 5 wearing a new one....

Janet

[CarlD]

My answer? When it's back within the residual levels suggested in the BG table for that CYA level or below 10--whichever is higher.

So if my CYA is 40, I'll swim when the FC is 10 or less (resid is 3 to 6)

If my CYA is 150 I'll swim when the FC is up to 15 (Resid is 8 to 15).

You don't have to follow my advice--that's simply what I do.