I wrote this post about what is in various products since this question of whether grocery/hardware store equivalents are really the same as pool store products comes up frequently from users new to these forums. Regular Clorox (Ultra in Canada) and off-brand Ultra bleaches are pretty much all 6% sodium hypochlorite, 4.7% sodium chloride salt and 88.7% water. Clorox has a very small amount of sodium polyacrylate in it as well (it is a mild metal sequestrant but as diluted in pools the amount is negligible).