Another shock question

[waterbear]

According to Ben's "Best Guess chart
http://www.poolforum.com/pf2/showthread.php?t=365
with a CYA level of 30 your min FC should be 3 ppm and your max 6ppm. This is the range you need to keep it at normally. If your CC is greater than .5 ppm you need to shock by raising you FC to 15 ppm.

You can have CC at any level of FC. It depends on whether there is enough 'reserve' of FC to 'burn off' the contaiminents in the water and break down the CC. If you have an outdoor pool without a SWG a CYA level of 30 ppm is a good choice.

Be aware that the pool frog is a silver/zinc system and had probably added metals to your water. You might want to read the section of the forum on metals
http://www.poolforum.com/pf2/forumdisplay.php?f=139