2 more questions about the shock process

[TonySe]

1. I have a Sand filter....should it be on "filter" or on "bypass" while shocking? I've had it on filter, and I backwash it every day (the PSI goes up by 10) and nasty green is coming out...but is it better to kill the stuff first, then filter, or to filter 24/7?
2. What FC level can one swim in a pool at? I'm guessing one should be swimming in a pool at an FC of 15, but I wanted to ask.

Tony

 

[jblizzle]

1. Either way.
2. Safe to swim up to the shock FC level depending on your CYA ... assuming the water is clear, you have low CC, and the pH is in range