CLEANING WATER TANKS

[eastmed]

my ss water tank developed some algae.
how this problem can be solved ?.
someone told me to put vinagre in the tank (20lt vinagre/200ltwater).
any kind advise will be most welcomed.

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[Jools_of_Top_Cat]

As the owner of a hot tub which if not treated, much like a swimming pool will soon have foul water.

Have you considered di-chlorine which will after treatment evaporate off. Try a garden centre for small quantities.

We use that and a UV filter which works well. I am surprised no-one has come up with a UV filter for water tanks on board yet, maybe there is a business oppertunity for me there...........

<hr width=100% size=1>Julian

<A target="_blank" HREF=http://www.topcatsail.co.uk>Top Cat Homepage</A>

 

[HeadMistress]

Fresh water system problems--foul odor or taste--are typically caused by allowing water to stagnate in the system. Although most people think only in terms of the tank, the plumbing is actually the source of most foul water, because the molds, mildew, fungi and bacteria which cause it thrive in damp dark places, not under water. Many people—and even some boat manufacturers—believe that keeping the tanks empty reduce the problem, but an empty water tank only provides another damp dark home for those “critters.”

There are all kinds of products sold that claim to keep onboard water fresh, but all that’s really necessary is an annual or in especially warm climates, semi-annual recommissioning of the entire system—tank and plumbing. The following recommendations conform to section 10.8 in the A-1 192 of the U.S. code covering electrical, plumbing, and heating of recreational vehicles including boats. The solution is approved and recommended by competent health officials. It may be used in a new system a used one that has not been used for a period of time, or one that may have been contaminated.

Before beginning, turn off hot water heater at the breaker; do not turn it on again until the entire recommissioning is complete.

Icemakers should be left running to allow cleaning out of the water feed line; however the first two buckets of ice—the bucket generated during recommissioning and the first bucketful afterward--should be discarded.

1. Prepare a chlorine solution using one gallon of water and 1/2 cup (4 oz) Clorox or Purex household bleach (5% sodium Hypochloride solution ). With tank empty, pour chlorine solution into tank. Use one gallon of solution for each 5 gallons of tank capacity.

2. Complete filling of tank with fresh water. Open each faucet and drain cock until air has been released and the entire system is filled. Do not turn off the pump; it must remain on to keep the system pressurized and the solution in the lines

3. Allow to stand for at least three hours, but no longer than 24 hours.

4 Drain through every faucet on the boat (and if you haven't done this in a while, it's a good idea to remove any diffusion screens from the faucets, because what's likely to come out will clog them). Fill the tank again with fresh water only, drain again through every faucet on the boat.

5. To remove excess chlorine taste or odor which might remain, prepare a solution of one quart white vinegar to five gallons water and allow this solution to agitate in tank for several days.

6. Drain tank again through every faucet, and flush the lines again by fill the tank 1/4-1/2 full and again flushing with potable water.

People have expressed concern about using this method to recommission aluminum tanks. While bleach (chlorine) IS corrosive, it’s effects are are cumulative. So the effect of an annual or semi-annual "shock treatment" is negligible compared to the cumulative effect of holding chlorinated city water in the tank for years. Nevertheless, it's a good idea to mix the total amount of bleach in a few gallons of water before putting it into either a stainless or aluminum tank.

And it’s that cumulative effect that makes it a VERY bad idea to add a little bleach to each fill. Not only does it damage the system, but unless you add enough to make your water taste and smell like a laundry, it’s not enough to do any good. Even if it were, any “purifying” properties in chlorine evaporate within 24 hours, leaving behind only the corrosive properties.

An annual or semi-annual recommissioning according to the above directions is all that should be necessary to keep your water tasting and smelling as good as anything that comes out of any faucet on land. If you need to improve on that, install a water filter. Just remember that a filter is not a substitute for cleaning out the system, and that filters require regular inspection and cleaning or replacement.

To keep the water system cleaner longer, use your fresh water...keep water flowing through system. The molds, fungi, and bacteria only start to grow in hoses that aren't being used. Before filling the tank each time, always let the dock water run for at least 15 minutes first...the same critters that like the lines on your boat LOVE the dock supply line and your hose that sit in the warm sun, and you certainly don't want to transfer water that's been sitting in the dock supply line to your boat's system. So let the water run long enough to flush out all the water that's been standing in them so that what goes into your boat is coming straight from the water main.

<hr width=100% size=1>Peggie Hall
Specializing in marine sanitation since 1987

 

[anchorhandler]

Hi Julian
Unfortunately a UV filter/steriliser has no residual effect, ie: it only works while water is being passed over it. To use a UV filter on board a boat, it would require the fresh water supply to be continuously flowing in order to remove bacteria. otherwise if the UV filter was switched off, bacteria could and probably would still accumulate in the tank and start to spread.
Best to stick with chlorinating as you mentioned earlier or invest in an elektro-katadyn system but that's beyond the realm of leasure boat practicality.

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[Quartet]

It's easy. Go to the Chandlers and get a tub of 'PuriClense' ( or something that sounds just like that, it is in a blue and white tub). Put the suggested amount of powder in the tank and mix it. ( Mix it in a jug or bottle if it is a solid tank with no access). Run it rhuogh the system until the treated water comes out of each tap, then shut the taps and go home. A week later, pump it all through, flush and hey presto - seriously clean. To keep it that way add Puri-tabs each time you fill up. You will not get green water or algae again, but there can be some residual taste. A decent in-line water filter will take that out.

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[Evadne]

I find a puri-tab plonked into our 40 gallon s/s tanks the first time I fill up each year is enough. It's less than the recommended dosage but the first tank full still tastes a bit swimming-pool-ish. After that it's quite potable. Once you've got rid of the inhabitants as recommended above, that is.

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[FergusM]

I clean my tanks and pipes using Milton solution from the chemists. It is used for sterilizing babies' feeding bottles, and I find it cheap and effective. Pour some into the empty tank, fill up with water and operate the pumps until the solution begins to come out of the taps. Leave for a while, then pump out, rinse, and that's the system clean and sterilized

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[chas]

Thanks for that - very useful.

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[VicS]

This topic has been discussed several times on the forum and a search or two should reveal loads.

Peggie Hall's advice is very comprehensive and although I support the idea of using a hypochlorite solution I would prefer not to use domestic bleach because it contains other constituents which may not be too good for you. It is after all sold for laundry use and for cleaning drains and toilets not as a treatment for drinking water. I would stick to Milton, after all if is suitable for babies bottles (which you do not rinse before use) it is not going to do you any harm. Only one word of caution; it has been said that manufacturers of flexible tanks do not approve the use of hypochlorite solutions but I can' t think why not.

<hr width=100% size=1><font color=purple>Ne te confundant illegitimi.</font color=purple>

 

[eastmed]

thanks

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[eastmed]

thanks !!

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[HeadMistress]

I'm not familiar with Milton's, so I can't argue your point except to say that household bleach--at least not that which is sold in the US--has any added ingredients that would be harmful....and that baby bottles rarely grow molds and fungi, but the plumbing in onboard fresh water systems does.

The issue, though, is whether any product actually does kill off all the "critters" in the pipes, or only knocks 'em back enough to improve the taste smell of the water for a while. I don't know how effective Miltons' would be in killing all of 'em off, but if it works as well the recommended bleach solution I can't think of any reason not to use it.

<hr width=100% size=1>Peggie Hall
Specializing in marine sanitation since 1987

 

[BrendanS]

Peggie, posted this once before. Milton is very pure Sodium Hypocholorite with salt to stabilise it. Many US bleach brands are fairly pure Sodium Hypochlorite. However, many bleaches in UK and Europe contain many other chemicals, some of which are actually harmfull to health. The original post contains a link to a scientific reference:

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While a standard household bleach would be fine for this sort of thing (the old type of bleach, which is just a sodium hypochlorite solution), most modern bleaches like Domestos are a mixture of sodium hypocholorite and disinfectants and detergents.

Many health specialists only advise using modern bleaches to treat what could be drinking water in emergencies, and where possible to use bleach without additives

This from the Pharmaceutical Journal, an authoritative and informed scientific journal of the Royal Pharmaceutical Society of Great Britain, not the multitude of quack doctor advice you can recieve on the internet:

"Household bleach. This can be used provided it is free of additives or disinfectants. Ordinary laundry bleach usually contains 4 to 6 per cent of available chlorine and one or two drops could be added to a litre of water. This method is probably best reserved for emergency situations where no other products are available." <A target="_blank" HREF=http://www.pharmj.com/Editorial/20000122/education/travelmedicine3.html>http://www.pharmj.com/Editorial/20000122/education/travelmedicine3.html</A>

Domestos and other normal household bleaches in the UK are not free of additive and disinfectants

Milton on the other hand is free of additives, and is highly purified.There is a reason for this.

Sodium Hypochlorite is unstable, creating Sodium Chlorate, often used as a weed killer. Responsible for this are impurities. The purified version when it comes in contact with protein, instead of breaking down into sodium chlorate, is converted into water and sodium chloride, common salt. This makes it a non-toxic fluid.




<hr width=100% size=1>Utinam logica falsa tuam philisophiam totam suffodiant

 

[HeadMistress]

Thanks for the information, Brendan. I was not aware that household bleach sold in the UK is any different from that sold in the U.S.

It actually sounds like Milton may be close to "U.S. grade" household bleach, so te most important things, then, are: 1. use enough of it to achieve the recommended "dose" of sodium hypochlorite; 2. don't treat only the tank, but the plumbing too, which means keeping the system pressurized so the solution remains in the pipes...and 3. leave it in long enough--at least 3 hours, up to 24 hours--but no longer, to get the job done without damage the system.

Vinegar used as I recommended earlier should remove any lingering aftertaste/smell of chlorine. And btw, the same treatment, including vinegar at the end, also removes the lingering taste/smell of antifreeze.

Thanks again!

<hr width=100% size=1>Peggie Hall
Specializing in marine sanitation since 1987

 

[BrendanS]

Hi Peggie,

Don't think it's commonly known. However, Clorox's own website (Clorox is often recommended for these purposes) show that it is a pure sodium hypochlorite solution - "Sodium hypochlorite is manufactured by mixing chlorine with sodium hydroxide and water. Following testing to ensure proper strength and filtering to remove any impurities, the sodium hypochlorite bleach is bottled. Except for quality control improvements, Clorox bleach remains unchanged since its introduction to American consumers in 1916."

The equivalent bleach brand in the UK contains anionic surfactants, disinfectants, brighteners and a whole bunch of other stuff.

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[HeadMistress]

This only demonstrates one of the disadvantages to my being in the US and giving advice to people who aren't. I've also learned recently that while US law has required the elimination of phosphates and other pollutants from all laundry detergents and other cleaning products sold here since the late '70s , that isn't the case in many other countries...even many of the same brand names--Tide laundry detergent, for instance, is also sold in Mexico and still contains all the pollutants that are banned here.

All of which means that my participation in these forums provides both a learning experience as well as (I hope) an opportunity to provide some useful help. So don't hesitate to correct me when I recommend something that isn't the same product that's sold in the US.

<hr width=100% size=1>Peggie Hall
Specializing in marine sanitation since 1987

 

[MainlySteam]

No, No, it is a real advantage, not a disadvantage you being in the USA Peggy - we have the same bleach as you except is 3%. Great stuff /forums/images/icons/smile.gif.

John

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[BrendanS]

Peggie,

As you say, something you cannot know about unless you have access to local information. It's one of the reasons I've been recommending using bleach here with some caution in many threads on the subject, unless people are clear what the ingredients of their particular bleach are - in the UK, Milton is a safe source, though quite expensive for this application

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[MainlySteam]

What about the stuff you throw in swimming pools - normally calcium h. not sodium h. I think but am not a swimming pool owner so not sure, but I assume it does not have stuff like surfactants, flavours, perfumes, etc, etc added. Long ago used it for bleaching (no I was not into tie dying) and did that just like the sodium stuff at a fraction of the cost.

Perhaps there is something bad it produces (is that why they say don't drink the swimming pool water?/forums/images/icons/frown.gif) but given one has to flush the tanks to get the water drinkable, does it matter.

Not promoting, just asking.

John

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