oldave wrote:

It's modern math!!! You can get any answer you want.

TechWriter wrote:


Per NFPA 1192 Standard on RVs, use 1/4 cup bleach per 15 gal of water (50 ppm ratio). So for a 90 gal RV water tank, you would use 1 1/2 cups of bleach. Run the bleached water throughout the RV plumbing, let it stand for 4 hours, then thoroughly flush with fresh water. For a stronger dose (100 ppm), you would use 1/2 cup of bleach per 15 gal water.

If you don't like using bleach, then you can sanitize your tank with Purogene

On the other hand, if you want to sanitize the water, and not the water tank, then you're talking about adding drops of bleach. Here are the EPA's Recommendations.