Scaling water storage from a 72-hour kit to a real household reserve changes the math and the failure modes.
How much: 1 gallon per person per day is the floor, not the target — it barely covers drinking, not cooking or hygiene. For a 2-week household reserve, that's a minimum of 14 gallons per person; plan for more if you have infants, anyone pregnant or ill, or pets.
Storage containers: Food-grade plastic (HDPE, marked with a "2" recycling symbol) only. Reused non-food containers (old milk jugs, etc.) can leach residue and degrade faster. Keep containers off concrete directly (chemicals can leach through) and out of direct sunlight, which promotes algae growth even in sealed containers.
Rotation: Commercially bottled water has a printed date; treat it as a real deadline. Home-filled tap water in sealed, food-grade containers is typically good for 6-12 months — write the fill date on the container itself.
Bigger reserves (55-gallon drums, rain catchment): Once you're storing serious volume, plan for a way to move and treat it — a drum you can't lift or pump from is theoretical storage, not usable storage.