sanitizing fresh tanks - basic question

It seems many campers consider sanitizing to be a major event. It can be a really simple process: let the water drain from the HW and FW tanks, add bleach/water, open faucets to fill with sanitizing solution, drain, fill with fresh water and open faucets long enough to drain out the sanitizing solution. This should not be a big deal. It should involve less than 10 minutes of actual work and less than 2 hours time for soaking and filling and draining. The bleach only costs a few cents. So why not be on the safe side. I sanitize if the RV has been unused for several weeks and maybe once or twice a year if in continuous use.

well i guess i’ll clean the hw tank next go round.

i’m not too worried about this. we only put city water in, or rarely campground water filtered through a blue grenade. we do go many months without using so sanitizing once a year seems prudent.

way2roll wrote:

JimK-NY wrote:
I am not at all concerned about algae growth. The concerns are mold and bacteria. They can grow amazingly quickly in the dark. Once growth starts, regular chlorinated water is not sufficient. Growth can become rapid in unchlorinated water and in previously chlorinated water. The chlorine dissipates pretty quickly even in a mostly sealed RV water tank. As I remember the half life is only a week or so.

Pipes and plumbing lack adequate amounts of food and oxygen for mold to grow.

Yep. And as for the chlorine half life, I think most people will use up their fresh tank contents within 1 to 2 weeks of use. So unless you are keeping water in the tank unused for months at a time, the chlorinated water will be enough.

Don't know how effective it is, if it is effective at all, but have been using the water freshener stuff available at Wally & camping supply stores for quite some time.

The method is to dump an ounce or so into the hose then proceed to fill the tank (100gal). We don't use city water directly. Everything, except for drinking water, goes into our tank first, after passing through a water softener.

It is a basic method carried over from our boating days when we needed to carry all water needed. No such thing as hookups when you are on 'the hook' in some remote place.

This is one of those "over kill" issues. Do this, don't do that, watch out for this...

Why pour the bleach down the hose? I just put about a cup directly in the water inlet and immediately flush it down with the hose. City water is chlorinated, so I am not concerned about "hose water". Run all the faucets like you do, wait a few hours and then flush everything. I do it once. Never "tasted" bleach nor smelled it. Been doing this for over 30 years, no problems.

I do not sanitize the HW tank. I flush it and refill it and turn it on when we are ready to go. I read somewhere that the heat generated will sanitize it all by itself. Again, 30+ years, no one sick, no strange rash like symptoms, no breathing difficulty and we sleep like babies. Keep it simple.

JimK-NY wrote:
I am not at all concerned about algae growth. The concerns are mold and bacteria. They can grow amazingly quickly in the dark. Once growth starts, regular chlorinated water is not sufficient. Growth can become rapid in unchlorinated water and in previously chlorinated water. The chlorine dissipates pretty quickly even in a mostly sealed RV water tank. As I remember the half life is only a week or so.

Pipes and plumbing lack adequate amounts of food and oxygen for mold to grow.

To sanitize the HW tank, you need to remove the plug, let it drain, replace the plug and fill after adding bleach and filling the fresh water tank. To do this I need to run the water pump for several minutes to fill the tank. Then you need to open the HW faucets and shower to soak those lines and fixtures. After the soak time, you need to again remove the plug and drain the tank. Then fill with fresh water and purge the bleach out of the lines.

I promise I wasn’t trying to stir up a hornet’s nest!

I finished. I drained the rinse straight onto the ground after flushing through the faucets a minute or two. That water is safe for plants and such, no reason to wait thirty minutes on the water pump.

Question remains about the hot water heater. After doing all of the above, I wanted to replace the anode rod, when I pulled out a bunch of water came out. So clearly that was’t drained when the fresh tanks were empty. Was it sanitized? If not how would I do that?

I am not at all concerned about algae growth. The concerns are mold and bacteria. They can grow amazingly quickly in the dark. Once growth starts, regular chlorinated water is not sufficient. Growth can become rapid in unchlorinated water and in previously chlorinated water. The chlorine dissipates pretty quickly even in a mostly sealed RV water tank. As I remember the half life is only a week or so.

Unless you already have extensive algae growth in the tank, you don't need to shock it. You just need enough to kill what few spores are there. And as the tanks are not subject to sunlight, algae growth shouldn't be a big issue.

Also, if you fill your tank with chlorinated city water, then you already are killing bacteria. It's only if you leave the tank filled for months at a time that you really need to sanitize.