Quote Originally Posted by ratgirl
Stabilizer . . . . . . Min. FC . . . . Max FC . . . 'Shock' FC
=> 0 ppm . . . . . . . 1 ppm . . . . . 3 ppm . . . . 10 ppm
=> 10 - 20 ppm . . . . 2 ppm . . . . . 5 ppm . . . . 12 ppm
=> 30 - 50 ppm . . . . 3 ppm . . . . . 6 ppm . . . . 15 ppm
=> 60 - 90 ppm . . . . 5 ppm . . . . . 10 ppm . . .. 20 ppm
=> 100 - 200 ppm . . . 8 ppm . . . . . 15 ppm . . .. 25 ppm

^^^That thing? I don't get it. I imagine what I want is shock FC, but what ppm would I want? That's confusing! So being that I have 5000 gallons rather than 10, I would be getting 12ppm from 1 gallon of ultra bleach? Would I want something that high?
Yup, you got it, all of it! You want the Shock FC level that matches your CYA/stabilizer level. And, yes, you would want a MINIMUM FC level of 12 ppm to clear your water--more if you have more CYA.

You can use the bleach calculator if the math is a struggle.