Thank you CarlD, I appreciate the quick response you gave me. I have yet to shock my pool as I am out of supplies. I have approximately a 13k gallon IG pool and want to shock to the 20ppm with the pool currently at about 5ppm. Is it possible to estimate how many bottles of bleach I should buy from say my local Walmart (8.25% Sodium Hypochlorite)? I will of course buy more to have on hand for keeping the chlorine at the correct level, but I do not have my Taylor book with me (which might tell me how much I need).

Thanks.