cancel
Showing results forย 
Search instead forย 
Did you mean:ย 

sanitizing fresh tanks - basic question

rvshrinker
Explorer III
Explorer III
80 gal fresh tank

I have 10% bleach (labeled Chlorinating liquid, which I use to do my pool following the TroubleFreePool Method).

Most sites say 1/4 cup bleach per 16 gallons which would be 1.25 cups for my 80 gallons. But this is for standard bleach which is 5.25%.

So am I ok to put about 2/3-3/4 cup of my 10% bleach in?

And the procedure is:

1. pour the bleach in the hose
2. run the water through the hose and fill the tank
3. run all the faucets and toilet and so on
4. let this all sit 8-24 hours
5. drain
6. (replace hot water heater rod)

Thatโ€™s it? Then the next time I fill I can just pour water in? Do I need to fill and drain now? It seems like a waste of 80 gallons of water.
27 REPLIES 27

JimK-NY
Explorer II
Explorer II
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.

rvshrinker
Explorer III
Explorer III
well i guess iโ€™ll clean the hw tank next go round.

iโ€™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.

toedtoes
Explorer II
Explorer II
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.
1975 American Clipper RV with Dodge 360 (photo in profile)
1998 American Clipper Fold n Roll Folding Trailer
Both born in Morgan Hill, CA to Irv Perch (Daddy of the Aristocrat trailers)

Veebyes
Explorer II
Explorer II
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.
Boat: 32' 1996 Albin 32+2, single Cummins 315hp
40+ night per year overnighter

2007 Alpenlite 34RLR
2006 Chevy 3500 LT, CC,LB 6.6L Diesel

Ham Radio: VP9KL, IRLP node 7995

aftermath
Explorer II
Explorer II
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.
2017 Toyota Tundra, Double Cab, 5.7L V8
2006 Airstream 25 FB SE
Equalizer Hitch

way2roll
Nomad III
Nomad III
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.
2023 FR Sunseeker 2400B MBS

JimK-NY
Explorer II
Explorer II
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.

rvshrinker
Explorer III
Explorer III
I promise I wasnโ€™t trying to stir up a hornetโ€™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 wasโ€™t drained when the fresh tanks were empty. Was it sanitized? If not how would I do that?

JimK-NY
Explorer II
Explorer II
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.

toedtoes
Explorer II
Explorer II
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.
1975 American Clipper RV with Dodge 360 (photo in profile)
1998 American Clipper Fold n Roll Folding Trailer
Both born in Morgan Hill, CA to Irv Perch (Daddy of the Aristocrat trailers)

JimK-NY
Explorer II
Explorer II
toedtoes wrote:
I agree with the time frame being overdone. You only need it to sit an hour or two at max.

Chlorinating liquid is usually used at a level of 52-100 ounces per 10,000 gallons in pools and is added every 24 hours. More than that can damage liners, etc. I personally wouldn't use more than an ounce or two for an 80 gallon tank. In that concentration, it will clean up any growth in the tank as well as it does in the pool.


I think you need to compare shock treatment for a pool, not routine chlorine use. Shock treatments are usually in the range of 2 or more gallons/10000 gallons of pool water. Pool chlorinating solution is typically about 12.5%. That works out to about 4 or more gallons of household bleach; i.e., 512 ounces per 10,000 gallons or roughly 4 ounces (1/2 cup) for an 80 gallon RV water tank. That would be the minimum I would want to use. As with the more is better for soak time, I would guess you are right and the amount of chlorine actually needed is about a fourth of the amount normally recommended.

dodge_guy
Explorer
Explorer
I donโ€™t measure. I just pour the bleach in (whatever method works) then fill the tank. I have a 40 gallon fresh tank. Iโ€™m sure I use more than a cup. But I know itโ€™s sanitized! Then you need to flush it with fresh water to reduce the chlorine/bleach smell.
Has worked great for me for many years.
Wife Kim
Son Brandon 17yrs
Daughter Marissa 16yrs
Dog Bailey

12 Forest River Georgetown 350TS Hellwig sway bars, BlueOx TrueCenter stabilizer

13 Ford Explorer Roadmaster Stowmaster 5000, VIP Tow>
A bad day camping is
better than a good day at work!

toedtoes
Explorer II
Explorer II
I agree with the time frame being overdone. You only need it to sit an hour or two at max.

Chlorinating liquid is usually used at a level of 52-100 ounces per 10,000 gallons in pools and is added every 24 hours. More than that can damage liners, etc. I personally wouldn't use more than an ounce or two for an 80 gallon tank. In that concentration, it will clean up any growth in the tank as well as it does in the pool.

And, by using a lesser amount, you won't have to rinse the tank to get rid of the excess chlorine.

Also, the rinsing of the tank is done mostly to get rid of the bad taste that is added to household bleach. When using pool chlorine, that bad taste is not added, so you don't need to eliminate it. After draining the tank of the chlorine, any chlorine left should be within safe drinking water level. You can always use a pool test strip to verify.
1975 American Clipper RV with Dodge 360 (photo in profile)
1998 American Clipper Fold n Roll Folding Trailer
Both born in Morgan Hill, CA to Irv Perch (Daddy of the Aristocrat trailers)

shum02
Explorer
Explorer
ktmrfs wrote:
while bleach is a good and quick way to sanitize, getting the bleach smell and taste out of the system, especially since some of the materials absorb the bleach to some degree, I don't use bleach.


I'll fill the fresh water tank of approx. 35 gallons, add a cup of regular white vinegar, let sit for an hour or so then run it through the lines. Bleach smell and taste is gone and the vinegar only last for a little while then disappears.
2006 F350 Lariat FX4 CC 4x4 PSD
2007 KZ2505QSS-F Outdoorsman