I am leaving in the morning for a 10 day vacation. Pool has been vacuumed and cleaned, just tested at my FC is at zero and my CC is at .5, My current CYA level is 30. I am planning to add chlorine tonight, but wasn't sure if I need to bring to a shock level of 12 or just get FC back up to 4? Also I have someone coming over to add chlorine, and I have advised them to add 50 ounce every 2 days? HELP? Do I shock tonight? or just get FC back up to 4, and then is the amount added every 2 days going to be ok (no one will be swimming in it for the 10 days)?????