i dont 'store' any water. but both bleach and peroxide are great disinfectants. i would lean towards bleach my self. for my aquarium i dispense the water a day or so before i need it to let the chlorine in tap water gas out. works great. both decay over time and bleach wont last long in warm temps. so if you keep it around for disinfecting water get a new jug every few months. its stronger in the summer btw because the heat decays the bleach and the manufactures have to keep a certain percentage to tout its properties.
peroxide goes bad quick once the bottle is opened.
if your gonna store a bulk of water an RO filter would probably give you the best results.
to liter bottles will start to decay if left to long so i would also swap those every few years.
if you got the cash im thinking a stainless tank would be the best bulk storage.
all the apartments i lived in come and flush the water heaters once a year. i could be mistaken but that is what is recommended.
oh if you wanted to go all out you could get a water buffalo from the military

trailer and everything