How do you sanitize your fresh-water tank and lines?

I would not want to argue with anyone who wants to use their camper without sanitizing the tank. But the OP asked for instructions on how to do the sanitizing using minimal amount of water.

The recommended procedure is to use 1/4 cup of household bleach for each 15 gallons of water. Pump the solution through the supply lines and faucets.

Some people bypass the hot water tank. I do not. There have been numerous studies showing that Legionella bacteria can thrive in RV hot water tanks. Fortunately most of us tolerate exposure fairly well. I had a friend who got really sick and was hospitalized with it for several weeks. I also do not scrimp and I completely fill the FW tank.

There are all sorts of conflicting instructions regarding the soak time. The original studies showed one hour was sufficient, but it seems that it is common to recommend longer soak times including even overnight.

Rinsing out the bleach solution will require a considerable amount of additional water. I completely drain the FW tank and pull the plug to also drain the HW tank. Typically I fill the tanks with fresh water and then drain again. You could probably get rid of the excess bleach by only filling the tanks about a third full and then drain again. Once you have the tanks flushed out the bleach in the supply lines can be quickly pumped out.

I use "spring fresh" santizer, easier than chlorine to get any residual smell/taste out. I do it every spring. The rest of the camping season I drain fresh tank after each trip, fill before the trip.

3 tons wrote:
Never done it in 14 years - I can visually see up close both ends of the fresh tank and it is still spotless

My eyes aren't as good as yours. I can't see bacteria.

3 tons wrote:
BTW, cith water has chlorine in it and apparently this is enough to do the job…

All campgrounds don't have chlorinated water supplies.

OP, I think most folks, including myself, sanitize our RV water tanks periodically. Once or twice a year for me.

I use either bleach or Purogene. Bleach is cheap, but caustic as hell. Purogene is pricey but easy on people.

For a typical 50ppm bleach sanitize, it's 1/4 cup bleach per 15 gal of holding tank capacity and let sit for 4 hours. For a stronger (100 ppm) concentration, it's 1/2 cup bleach per 15 gal and let it sit 1 hour.

Finally, you'll probably get some interesting rationale from folks who never sanitize their water tanks like . . .

- "I haven't gotten sick yet." (Also a popular excuse for smokers.)

- "I used to drink out of a water hose when I was a kid" (What this has to do with tank sanitation still escapes me.)

I follow the instructions - Bleach and a lot of water to rinse it out after the first fill and sit period.

Never done it in 14 years - I can visually see up close both ends of the fresh tank and it is still spotless…BTW, cith water has chlorine in it and apparently this is enough to do the job…

3 tons

I don't.