RV OWNER’S FIELD GUIDE · PLUMBING
Fresh Water Tank Sanitizing
Worth doing at the start of every season, after any period of storage, or any time the tank sat with water in it for a while.
The Standard Ratio
Use about ¼ cup of unscented household bleach per 15 gallons of tank capacity, mixed with water and added to the tank. Run the mixture through every faucet (hot and cold) until you smell chlorine at each one, then let it sit a minimum of 4–12 hours — overnight is easiest.
Draining and Rinsing
Drain the tank completely, then refill with fresh water and drain again through every faucet at least once, twice if you can still smell chlorine strongly. Skipping a thorough rinse is the most common reason people end up with lingering bleach taste for days afterward.
Fixing a Lingering Taste
A baking soda rinse (dissolved in the tank, drained after a short soak) neutralizes remaining chlorine smell faster than plain water alone. Running an inline carbon filter for the first tank or two afterward also clears any residual taste quickly — see our filtration guide.