1/4 cup of bleach per gallon of water is way too much for sanitizing.
Palmer recommends 1 tbsp per g. (See here
I believe Papazian recommends a lesser concentration.
Bleach is very powerful stuff, and can cause some really unpleasant off flavors if excess remains in the brew while fermenting.
If you have Iodophor, why not use that instead for all your sanitizing. It costs a bit more than bleach, but is 10 times faster, and doesn't require any rinsing (which can cause infections).