# Cleaning of DRINKING water tanks



## 91929 (May 1, 2005)

:? I am looking for answers to cleaning out the drinking water tank.
i have read various methods All involve the use of some chemical agent or other. Having read the instructions for 2 off these the small print warns against using them where metals are involved
Hdoes this effect the water pump (not having had one appart yet I dont know if any metal is involved) I have a hot water storage tank (it may have a plastic lining but will the immersion heater)

PamNPete


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## autostratus (May 9, 2005)

We use the powdered steriliser sold through accessory shops for that purpose. As it is a recommended product it should be safe to use.

Although you add it to the water and leave for a little while it is not really that long in contact with anything metal and is flushed through at the end of the time.

Probably safer than the home made treatment of using liquid chlorine bleach. I refer to Milton which many people use. Could just as easily use Domestos as it's the same chemical product ie sodium hypochlorite and cheaper.


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## 88724 (May 9, 2005)

Hi 

Miltons or boots equivilent would be my recomendation, its used for sterilizing babies bottles.

Gillian you "appear" to hold a different view on Miltons or does your post read wrong ?


George

Changed This "appea" to this "appear"


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## Jeffus (May 1, 2005)

autostratus said:


> Probably safer than the home made treatment of using liquid chlorine bleach. I refer to Milton which many people use. Could just as easily use Domestos as it's the same chemical product ie sodium hypochlorite and cheaper.


Yes I, like George would like to know too Gillian. You would think a product like Milton, used with babies would be 100% free of any bleach products. Milton compared with Domestos?????? Does anyone know if this is true? Jeffus. 8)


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## spykal (May 9, 2005)

Hi PamNPete

When I clean my tank ( with Milton) First of all I make sure that the system is full of clean water ( The heater tank etc) then I drain the fresh water tank from the drain down pipe, then I fill the fresh water tank adding the correct amount of Milton, then after leaving it to soak for the required time I pump some of it through the whole system using the pump and the hot and cold taps. Then I drain down the system and add some fresh water to the tank and flush through a couple of times finally refilling with fresh water.

Doing it this way ensures that the cleaning agent does not come into contact with the metal parts in the system whilst in the "soak" stage.

Mike


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## autostratus (May 9, 2005)

Sodium hypochlorite is the chemical term for liquid bleaches such as Parazone, Domestos and in a more dilute form Milton. I have no problem with the proper use of the chemical product in any of its forms be it for use in sterilising header tanks in industrial air conditioning systems to prevent Legionaires Disease, its use in swimming pools or for that matter in sterilising babies bottles in its Milton form.
These are all legitimate uses with measured doses for the different situations.
What bothers me is the use of the chemical in an uncontrolled way. In all of the advice I've seen advocating its use for sterilising mh water tanks there has never been a recommended dosage.
How do you know if too little has been used and your tanks are not sterilised? Do you want gippy tummy while on holiday and caused by your own tanks?.
How do you know if you are using too much and affecting the parts that can be affected by an overstrength solution.
The answer is that you don't know unless you use a measured recommended dose.

We use Puriclean which again is a bleach but in powdered form.
The recommended dose is one teaspoon per 4.5 litres (1 gallon).
It costs about £1.00 to clean our system and we know it has done what it is supposed to do.

Jeffus, there's nothing wrong with using a bleach product in measured amounts on babies bottles, we're talking of sterilising a glass product which is left to drain before use.

Incidentally, we don't drink the water from our tank but prefer to use water from 2x 5 litre containers which we fill up regularly. We also sterilise those containers.


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## spykal (May 9, 2005)

Snipped


autostratus said:


> Incidentally, we don't drink the water from our tank but prefer to use water from 2x 5 litre containers which we fill up regularly. We also sterilise those containers.


We do the same.

and there is no problem using Milton , all the info you could want is to be found on the website:

http://www.milton-tm.com/tips/campingtips.htm

Mike


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## RichardandMary (May 9, 2005)

Hi PamNPete

Milton I am told should not be allowed to come into contact with stainless steal (sinks inside of water heaters) as there is a reaction causing the steal to corrode

Regards
Mary/Richard


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## Anonymous (Nov 10, 2000)

We have been using Milon to flush our tanks and for general cleaning for a year. We have not been ill, sinks are still shinny and all plumbing, pumping things are working fine. Will let you know if things go bottoms up, though


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## 89539 (May 27, 2005)

Hi PamNPete,

We have adapted a tip that came from the mountain biking community (most cyclists use packpack drinking systems these days and they are also prone to getting a bit musty).

The answer .... Sterident. I use about 4 or 5 tablets in our tank. Does a great job and leaves the water tasting minty (after a good flush with clean).

It doesn't stop the silly looks I get at Tesco buying the stuff (I'm still a bit young to need the product :lol: )

Pete


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## 91929 (May 1, 2005)

*Cleaning Water Tanks*

 Hi ALL
Milton is the product which should NOT be used on metals. Baby's bottles are not metal, but glass, plastic, or similar products.

We bought some milton for the purpose of using it in the tank then found the small print. I have seen the results of VERY MILD acids on the metal around sink plug holes, The chrome dissapears

Thanks to all those who replied, think I'l use the powder from the camping shops 8)


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## Anonymous (Nov 10, 2000)

I used Puriclean to clean out my freshwater tank. Doesn't cost any more than using anything else & I know it is designed for the job.
As a Mother who regularly used Milton and Boots own brand sterilising tablets for sterilizing my baby's bottles I can most certainly state that it is a bleach. After using a tankful for the bottles I used to use the solution for all manner of cleaning jobs like soaking bibs to get the stains off, getting stains off crockery, etc. The baby's bottles had to be rinsed in freshly boiled water before use to get rid of the sterilising fluid, so you don't actually feed the Milton solution to the baby!
On a slightly different tack, I remember my Parents used to use tablets of some sort in their motorcaravan fresh water tank, but from what I recall they used to throw a tablet in each time they filled up & it made the water safe for drinking, they didn't flush it out. They used to get them from Boots - think they were designed for people to take with them when going abroad & wanting to make sure the local water was safe. Anyone know if you can still get them?


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## spykal (May 9, 2005)

Caz said:


> I remember my Parents used to use tablets of some sort in their motorcaravan fresh water tank, but from what I recall they used to throw a tablet in each time they filled up & it made the water safe for drinking, they didn't flush it out. They used to get them from Boots - think they were designed for people to take with them when going abroad & wanting to make sure the local water was safe. Anyone know if you can still get them?


Hi Caz
I remember the tablets too, made the water taste a bit iffy, in fact the way our tap water tastes now! Chlorine.

If you want you can use Milton to do the same thing, tells you how on the web site....and, before you ask, no I don't have shares in Milton pharmaceutical :lol:

Mike


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## Jeffus (May 1, 2005)

*Re: Cleaning Water Tanks*



PamNPete said:


> Hi ALL
> Milton is the product which should NOT be used on metals. Baby's bottles are not metal, but glass, plastic, or similar products.
> 
> We bought some milton for the purpose of using it in the tank then found the small print. I have seen the results of VERY MILD acids on the metal around sink plug holes, The chrome dissapears
> ...


Mornin' all, I'm getting really confused here about the use of Milton AND the waterheater+taps+metal etc. Looking in my Bessacarr owners manual they RECOMMEND Milton 2 for complete sterilisation of the water system. I presume that includes the water heater as that is fed from the fresh water tank. I have sent off for the information from Milton and I'll keep you posted on what they say. Jeffus. 8)


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## Anonymous (Nov 10, 2000)

As a Father who regularly used Milton and Boots own brand sterilising tablets for sterilizing 5 of my baby's bottles I agree with Caz it is a bleach.

Bleach is a dangerous chemical to all forms of life and should be used with caution and avoided where possible.

It is e.g. inadvisable to get tea stains of cups with bleach however much you rinse them afterwards.

I would like to know what is the best way here.

1...When not using the m\home, should the water tank be left full or empty and dried out.

2...Should the port pottie (sorry) when not being used for some time be left without chems in or just water in or nothing in and should the valve be left open for air or closed.

Before we went on hols, I shoved a whole bottle of milton in the water tank, left it there for some time, and then ran it through everything into the waste tank and then left that there for some time and then emptied the lot. I then filled up with fresh and did the same thing twice. It now appears from reading above, my pumps will soon give up. I will let u know.


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## spykal (May 9, 2005)

*Re: Cleaning Water Tanks*



Jeffus said:


> PamNPete said:
> 
> 
> > I have sent off for the information from Milton and I'll keep you posted on what they say. Jeffus. 8)
> ...


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## Jeffus (May 1, 2005)

*Re: Cleaning Water Tanks*



spykal said:


> . . . the most vunerable (ihmo)being aluminium and the least vunerable stainless steel.
> I think we may be worrying overmuch about it, but disinfecting using these bleaches usually involves soaking the system for a given period and this if carried out very regularily could damage vunerable parts in a system . . .


Hi spykal, thanks for the link but again no mention of Milton being used with metal in their blurb. Most confusing. The water heater/space heater in the Bessie is the 6kw Truma Combi C. Do you think flushing it through with Milton will harm it at all? Remember in the owners manual Bessacarr recommend the use of Milton. Cheers good friend. Jeffus. 8)


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## spykal (May 9, 2005)

Hi Jeffus

On the bottle of Milton it just says "avoid prolonged contact with metal" and listed as an ingredient Sodium Chloride (16%) which is common salt so even if the bleach ingredient was safe with metal you would not want to leave this in the system for too long.

It will be interesting to see if they give an adequate reply to your enquiry.

Mike


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## autostratus (May 9, 2005)

Can I in a sense add a postscript to this topic and say "Thank you", to all those who have contributed and in particular to Mike (spykal).

I've seen a number of questions over a few years in which the same question has been raised and similar answers ie use Milton have been given.
I have some experience with bleach (sodium hyperchlorite) and I always advised against its use for motorhome tanks on the basis that no one ever gave a dosing formula. On that basis I was opposed to its use having seen and heard many examples of the results of its misuse in other fields.

We now have a website http://www.milton-tm.com/tips/campingtips.htm which gives a dosing procedure and on that basis will probably be using Milton for our own tanks.


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## 91929 (May 1, 2005)

*cLEANING water tanks*

Hi from PamNPete (to all repliers again)

*Caz* The tablets are (or were) sold as water purifing tablets at GOOD climbing outlets 
I think they are still available from the YHA sales or such as Blacks or whoever now owns them OH there is a firm in Appleby in Westmorland area who specialises in outdoor gear for out of the way places.

*PKC3* How much sterident would I need for a 20gal tank?? 
We use them for our flasks but thought they only work with warm water

*PUSSER* I once had a plastic tub type toilet in a caravan, before these new fangled flushing thingies came out.
Cleaned both that & the new cassett the same way (well almost)
When we get home from hols. I empty the loo @ flush out as on site 
Then we clean down the oven top drainer etc @ pour into the loo. Clean out the fridge & use a small amount fo disinfectant in the water. This goes into the loo.
Empty the loo (by this time all residues should be removed)
Then replenish the blue stuff, Spray that stuf for the lid onto it @ place back in the van leaving lid open 
By the way dont forget to open the lid (at least part way) when going over high mountain passes to prevent pressure build up
Then if we have to use the loo when on a day out it is ready
If you want (or think it necessary) there is some stuff to clean out the loo tank & some more to clean out the black stuff that sometimes appears in the flush water, you cant leave it in though as it is not good for the rubbers


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## autostratus (May 9, 2005)

*Re: cLEANING water tanks*



PamNPete said:


> Hi from PamNPete (to all repliers again)
> 
> *PUSSER*
> When we get home from hols. I empty the loo @ flush out as on site
> ...


A little while ago there was an article in En Route (the CC magazine) written by the resident expert.
He wrote that *on-site* you could make use of the toilet cassette to get rid of waste water from an inboard tank after first emptying and cleaning the cassette in the usual place.

My view at the time was that people seeing you emptying the loo at the grey water drain (perhaps in the corner of the pitch) wouldn't know what was draining away. This could lead to a misunderstanding and argument.

Others didn't see it like that. Is it only me (as usual)?


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## Anonymous (Nov 10, 2000)

Thanks Pam&Pete... Do I understand that during our trip up and down and over Millau could have caused our full marine loo to explode. Jesus....I'm glad I have only just learned that. We could have devastated half of Europe with the amount we had on board.

Think I won't mention this to the missus.


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## autostratus (May 9, 2005)

I remember in the days when we had a Porta-Potti unit in a small toilet compartment in a caravan.
We'd previously had the bucket and chuck-it type of toilet and this new one was sheer luxury.
We were crossing France, climbing and were somewhere near Clermont- Ferrand. We stopped for a rest and something to eat and set up the caravan. I went into the toilet compartment to find the Porta-Potti was rocking about, a bit like those little figures you can knock over but they come back upright. The bottom half was very distorted.
Fortunately we remembered reading something about altitude and toilets so it was a case of stand back with the lid down and open the flap a fraction.

It immediately resumed its original shape and no harm was done but I can assure you it happens (or it did). Maybe they've altered them so it doesn't happen today.


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## Anonymous (Nov 10, 2000)

Spooky - that is where Millau is. Perhaps they should put up signs before the climb warning you of toilet explosions. I have just had a ridiculous road sign spring to mind.


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## 88790 (May 9, 2005)

CAK makers of tanks, as if you didn't know, recommend 'Chempro' For cleaning etc. They say it is used in the brewing industry etc. Looks a satisfactory answer to me from a company that should know about tanks and cleaning.

John 8)


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## 88781 (May 9, 2005)

Good one Jabber! never thought of Chempro..used to brew my own wine using that stuff..no taste or smell, obtainable from your local home brew shop.


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## spykal (May 9, 2005)

Hi all
Re Chempro, I looked it up on the net and thought I had found the holy grail of sterilisers, it does not attack metals, even aluminium. BUT according to uk.rec.caravanning newsgroup, they, Chempro, seem to have stopped selling it. May be worth trawling round the local home brew shops to see if they still have some left in stock.









Mike
P.S. i bet it got axed under recent bl**dy EEC rules that finished off loads of useful products for use in in the home and garden


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## RobMD (May 9, 2005)

I would echo a few of the posts above, I use Puriclean, which dissolves easily and leaves no after taste. It isn't expensive and is easy to use and store.

Once a year I normally use a full strength solution to sterilise the tank and all equipement (as directed), then give 2 rinses. For the rest of the year if the water has been in the tank more than a couple of weeks, I drain and refill it. With regular use it gets drained and refilled often enough.
For drinking water, I usually fill a filter jug from the tap and keep it in the fridge. for all other purposes including Tea and coffee I use water via the tap.

Never use Household Bleach. Pure (as in clean) sodium hypoclorite is used for cleaning tanks, and for dosing water for consumption, normally it would then pass through dechlorinator, but it tastes foul (Pusser probably knows about this), and unless used in the correct concentration can be dangerous to health.

In this country, it is unlikely that you will have problems with poor quality water, but other counties must be treated as suspect unless known to be O.K., and water in warm climates should always be treated with care.


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## 88724 (May 9, 2005)

Hi

Water in UK is generally good remember though that the treatment is only good for a couple of days max when it enters a tank.

I have fitted a water purification system URL test results here



















The above system is excellent Safe great tasting water, at the Demo at the NEC show they used a tank with loads of bleach and blue ink in, after filtration, same water was crystal clear and taste free.

According to test results extremely safe too

Geo[/url]


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## Anonymous (Nov 10, 2000)

We haven't had a problem with our water tanks. We tend to use bottled for drinking/cooking but the tank seems okay.

We use the 'van a fair bit so water doesn't tend to sit for more than about 10 days max. The only thing I've used to clean the tank is a solution of Bicarbonate of Soda, I can't remember where I read it or why it works but everything seems to be fine, it may of course be a coincidence!

I put a few tablespoons of the stuff in the filler pipe, than about 20 to 30 litres of water. A short drive around the block, about the only time speed bumps are useful! Then drain off and refill.


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## elbino (May 9, 2005)

Puriclean for cleaning the tank and Puritab tablets for treating the water available at every ccmping accessory shop I've ever been in. 3 tablets for our 80 litre tank. I was also given the tip when using Puriclean on the tank to drain it into the waste tank and leave for a few hours before flushing thus getting full use and value for money


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## RobMD (May 9, 2005)

Good comment elbino.


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## 89184 (May 16, 2005)

A number of contributors have mentioned Puriclean. The active ingredient is stated on the label to be 6% Sodium Dichloroisocyanurate and one pot of this will clean up to a 90L tank. As I have a 150L tank and the puriclean costs ~£3.50 a pot it seems expensive. 

Sodium Dichloroisocyanurate is also known as Cyanochlor and is used as an anti-bacterial in swimming pools. My local pool dealer sells 2Kg of 55% Cyanochlor for £15. A dose eqivalent to the recommended by Puriclean is 16g/150L. (this can be weighed on digital kitchen scales). So for £15 you get 125 tank treatments. 

Seems to work effectively.

Keith


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## elbino (May 9, 2005)

I hear what you say but the 400gm pot of Puriclean I bought will treat up to 270 litres tank for £4.99. That gives me 3.3 cleans at £1.51 a clean as we have an 80 litre tank. For twice a year thats £3 and only paying out £5 to start with. I realise that a big 150 litre tank is a different matter but buying 2kg of swmming pool cleaner at £15 would last for about 8 cleans or 4 years at the same dilution rate on the larger tank. Whilst the cost would be £1.88 a clean against £3 would the product last for 4 years?
I think I'll stick with the Puriclean


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## RobMD (May 9, 2005)

As I only clean the tank once per year, the cost of a tub of Puriclean is immaterial - I spend more than that on a magazine.


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## 89184 (May 16, 2005)

We have had problems in hot weather for prolonged periods in Spain/France where the water would start to smell "off" after about a week even though it was not static ie we were using and re-filling. A quich flush with cyanochlor for 2 hours solved the problem. So we always carry some and give a routine flush every 2 weeks if away for a while. Its good for cleaning out the waste tank too.


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