Easiest way to disinfect fresh water tank?

[UKDUDE]

Originally Posted by weirdstuff

Jekkerville...thanks for that info. Everyone else seems to think we need so much more chlorine though. Are you sure using so little will disinfect everything?!



We always use our fresh water hose to fill the tank. And yes, we're careful to always use potable water. Last time we filled tank was from the outside hose bib at our friend's house back in February.



And since we've only been day tripping since that trip in February, we don't use much water. We don't drink it, but our dogs do. And a couple weeks ago, I went to fill the doggie water bowl, and noticed the smell.



So, yes, this would be cold water. We haven't used the water heater in a long time.



And, not that you asked, but, our bathroom/toilet does not smell, so I figured this was just related to the fresh water tank, and not the black tank.

The EPA and other organizations publish material on how to disinfect a drinking water source. Here's a link to an example:
http://water.epa.gov/drink/emerprep/...sinfection.cfm


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[nrgtrakr]

WHO and most state public health departments also have procedures to follow to disinfect potable water storage tanks.

[Protagonist]

Originally Posted by UKDUDE

The EPA and other organizations publish material on how to disinfect a drinking water source. Here's a link to an example:
Emergency Disinfection of Drinking Water | Emergency Preparedness | US EPA

Emergency disinfection of drinking water is for adding chlorine to the water you're going to drink. It is designed to leave a chlorine residual of more than 1 part per million and less than 4 parts per million, in other words a safe level of chlorine for human consumption. That's not the same as disinfecting a freshwater tank. The document you linked to is near and dear to many Gulf Coast residents' hearts, because when a city floods during a tropical storm event, the city's water supply is compromised until the water mains have been thoroughly flushed. When we're under a "boil order" it's not always practical to boil the water if you don't have a heat source and/or don't want to drink hot water, so adding bleach to the drinking water is a viable alternative.

But the linked document does contain one important fact— use only unscented Clorox brand bleach, because it has consistent levels of chlorine in every batch produced, unlike some off-brands that may have varying chlorine content, so when you ad ounces or drops or whatever measure of bleach, you know you're putting in the right amount of chlorine to make the water safe.

If you're looking to shock-treat your RV's freshwater system and then flush it with fresh water to remove the chlorine, that's an entirely different matter and does require more chlorine. Your Airstream owner's manual— if you have one or can download one from the Airstream web page— should tell you how much chlorine bleach to add to your freshwater system to shock-treat it. My Airstream Interstate owner's manual says to multiply tank capacity by 0.13 to find the number of ounces of bleach to add. Since most Airstream Interstates have a 26-gallon fresh tank and a 6-gallon water heater, for a total capacity of 32 gallons, that is 32×0.13= 4.16 ounces of unscented Clorox bleach. Since fractions of an ounce are sometimes hard to measure, if you round up to 5 ounces you should do fine, because you're going to flush the system with fresh water afterward and aren't worried about leaving residual chlorine in the drinking water.

On Edit— The Airstream Interstate owner's manual also says to let the chlorinated water sit in your freshwater system for at least 4 hours. It also says that if you want to do it in one hour, double the amount of bleach.

[Marks71]

Originally Posted by Protagonist

Emergency disinfection of drinking water is for adding chlorine to the water you're going to drink. It is designed to leave a chlorine residual of more than 1 part per million and less than 4 parts per million, in other words a safe level of chlorine for human consumption. That's not the same as disinfecting a freshwater tank. The document you linked to is near and dear to many Gulf Coast residents' hearts, because when a city floods during a tropical storm event, the city's water supply is compromised until the water mains have been thoroughly flushed. When we're under a "boil order" it's not always practical to boil the water if you don't have a heat source and/or don't want to drink hot water, so adding bleach to the drinking water is a viable alternative.

But the linked document does contain one important fact— use only unscented Clorox brand bleach, because it has consistent levels of chlorine in every batch produced, unlike some off-brands that may have varying chlorine content, so when you ad ounces or drops or whatever measure of bleach, you know you're putting in the right amount of chlorine to make the water safe.

If you're looking to shock-treat your RV's freshwater system and then flush it with fresh water to remove the chlorine, that's an entirely different matter and does require more chlorine. Your Airstream owner's manual— if you have one or can download one from the Airstream web page— should tell you how much chlorine bleach to add to your freshwater system to shock-treat it. My Airstream Interstate owner's manual says to multiply tank capacity by 0.13 to find the number of ounces of bleach to add. Since most Airstream Interstates have a 26-gallon fresh tank and a 6-gallon water heater, for a total capacity of 32 gallons, that is 32×0.13= 4.16 ounces of unscented Clorox bleach. Since fractions of an ounce are sometimes hard to measure, if you round up to 5 ounces you should do fine, because you're going to flush the system with fresh water afterward and aren't worried about leaving residual chlorine in the drinking water.

On Edit— The Airstream Interstate owner's manual also says to let the chlorinated water sit in your freshwater system for at least 4 hours. It also says that if you want to do it in one hour, double the amount of bleach.

So many threads and posts on this topic.

If you're not talking about shocking or emergency disinfectant, Protag summarizes the manuals and the AI books, etc. 1/2 cup of bleach, 4 hours. Then what everyone else says about flushing and repeating with a clean, potable, rinse.

If you can arrange to be driving for those 4 hours, to slosh the water around, so much the better. So we do ours as we're leaving one location and heading toward another, both with hookups. Makes the filling, flushing, and rinsing convenient.

[nrgtrakr]

We've never used our water tank. So out of curiosity I looked in the owners manual. The owners manual states:

To clean the tank, pour some bicarbonate of soda into the filler spout with several gallons of water and allow it to stand for a minimum of four hours. Then flush the tank out by opening the drain valve and running fresh water through it.

If the water tank must be cleaned further, the following procedure is recommended.
1. Prepare a sodium hypochlorite solution using potable water and household bleach (5-1/4 or 6%) in the ratio of 1/4 cup of bleach to 1 gallon of water.
2. Pour 1 gallon of hypochlorite solution for each 15 gallons of capacity into the empty water tank.
3. Add enough potable water to completely fill the water system.
4. Allow closed system to stand for three hours.
5. Drain the hypochlorite solution from the system and refill with potable water.
6. Excessive hypochlorite taste or odor remaining in the system is removed by rinsing the system with a vinegar solution mixed in the ratio of 1 quart vinegar to 5 gallons water.
7. Drain the system and flush with potable water.
8. Drain the system and flush with potable water.

Simple! Thanks for the review!

[mocus]

I also use a little vinegar for some reason. Continue?

[AWCHIEF]

Back in my home brewing days we used iodine as a disinfectant. The military and the Boy Scouts also used iodine to disinfect iffy water supplies. Might be worth considering for folks that are nervous about using chlorine.

[NavyCorpsman]

Elemental Iodine is poisonous. It is one of my childhood memories after getting a cut... little glass vial with a glass applicator wand, burned like L, stained my skin and the cool but spooky little skull and crossbones on the label.
If you prefer Iodine, you would need to use Potassium Iodide. It's what we used in the field in our canteens. It would be doable but expensive.
Chlorine is safe(er) at trace levels, but yes can be just as bad as anything else at higher doses.

[Protagonist]

US Navy uses bromine instead of chlorine.
Model 6979 Potable Water Brominator | Howell Laboratories
Turns the water slightly pink, but supposedly tastes better than chlorine. Don't think they make a small portable model for RVs, though you can get one for a swimming pool. Just thought it was interesting.

[mandolindave]

I use the drain valves to drain, not the sink faucet. There at the lowest point, you get more water out, and that's what there meant for.

Also I try like heck not to drink trailer water. There are just too many ways for it to get contaminated, and a whole lot of work to keep the water safe. I still do the best that I can.

I really only dry camp. Some of the festivals I go to have a spicket to get water, and many advise not to drink it. Even if the water coming out of the ground is good, you never know what the person before you did to the nozzle, bib, hose, etc. I saw a guy shampooing his hair, rubbing the hose thru his hair to rinse. Like a jerk, I said something, and got a whole lot of noise about minding my own business, and not to give him a hard time.

[avanti]

Originally Posted by mandolindave

Also I try like heck not to drink trailer water. There are just too many ways for it to get contaminated, and a whole lot of work to keep the water safe.

Whole lot of work? Disinfect once a year as per manual with a bit of chlorine. Fill up with chlorinated city water whenever possible. Then drink up. You'll be fine.

[InterBlog]

Originally Posted by avanti

Whole lot of work? Disinfect once a year as per manual with a bit of chlorine. Fill up with chlorinated city water whenever possible. Then drink up. You'll be fine.

I think geography plays a significant role in the results that one can expect. Here in the subtropics, I cannot even keep my dog's water dispensers free of bacteria if they are allowed to set with any quantity for more than 48-72 hours. And that's at an indoor temp of 77 degrees, AFTER disinfection and AFTER re-filling with chlorinated muni water each time. Every time I turn around, I'm draining the reservoirs and scrubbing away more brown slime and pink slime and gosh knows what else.

We have our Interstate garaged and the average daily summer temp inside the unit is right around 100 degrees (no direct sun but re-radiation off the building's metal roof is fierce). In those conditions, overgrowth will occur within about 24 hours, so I gave up on all efforts to maintain a water reserve. I have taken to keeping the tank as dry as possible during these summer months, which is another form of inconvenience because then I'll take the Interstate out for a local spin to the beach after forgetting to add some water for the trip and, dang, I won't even be able to rinse off my feet or whatever. Brain lapse.

[wolf146]

Originally Posted by Jekerrville

Wierdstuff,


Chlorine is a reactant and it CAN damage features of a water system.

So, a tablespoon of chlorine in 50 gallons is going to be about 1000 PPM. Household bleach will be somewhat less than pool chlorine or USP chorine. No problem.

Correct me me if I am wrong on this.
1. I always thought that the hot water tank is made of aluminum.
2. If you are passing chlorinated water through the tank wouldn't this cause a reaction with the aluminum tank and produce aluminum chloride. Wouldn't that shorten the life of the tank?

wolf146

[Jekerrville]

Wolf146

I have searched high and low for aluminum hot water tanks and can not find a supplier so I am going to go out on a limb here and say that there is not such a beast in an AS.

Fuel tanks, expansion tanks, water bottles yes, but not hot water tanks.

In the beverage industry aluminum cans are lined to prevent just the type of oxidation you mentioned in your post.

If an aluminum hot water tank is available I suspect it too is lined with non-reactant coating of some sort.

In my post previously quoted I suggested a very mild application of chlorine in potable water to be sufficient to purge bacteria but not so strong as to harm the plumbing.

Sorry if I did not make my self clear.

Regards

[Protagonist]

Originally Posted by Jekerrville

I have searched high and low for aluminum hot water tanks and can not find a supplier so I am going to go out on a limb here and say that there is not such a beast in an AS.

It is a very thin limb. Check the orange text box at the bottom left corner of the first page of the brochure in this link:
http://www.askforatwood.com/images/W...ceTri-Fold.pdf
Is specifically says "Atwood water heater tanks are composed of a high strength aluminum."

[Jekerrville]

What is the inside of the tank lined with?

[wolf146]

Thank you gentlemen for your reply. So I guess you would want to limit the amount of chlorine that gets into the hot water tank. wolf146

[leedav]

Maybe this is unorthodox and a little more expensive but I am trying this

- when storing for just a couple weeks
- fill tank with water treated with aquamira
- run it into the faucet also
- before camping drain and fill with filtered water from home. (We don't favor the taste of aquamira... But our earthquake emergency barrels are treated with it)

[InterBlog]

A few days ago, my husband asked me this question: Why can't we simply get one of those UV lights and stick it in the top of that fresh water tank and kill the incessant slime that way? Even if we still decline to drink the water, at least it would stop clogging the danged pump filter.

Ultraviolet germicidal irradiation - not a new technology, but not used in RVs to my knowledge (but I haven't researched it yet).

Portable use, yes - for instance the product SteriPEN, widely touted as a cheap travel solution to Montezuma's Revenge. For years, hand-held UV devices have been advocated for back country use, but I always defaulted to my K.I.S.S. solution, which is the JetBoil, one of the greatest consumer products ever invented. With a hand-held UV device, maybe you can kill some water microbes, but a JetBoil does that PLUS it makes Mountain House meals and tea.


I've added this idea to my must-look-into-it list. It's a long list.

[toskeysam]

Back in the days of wagon trains.......silver coins were put into the water barrels. The silver ions, generated by the coins sloshing around in the barrel, kept the water potable. Too bad we don't have silver coins anymore.


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