Cleaning water tanks

Not necessarily true. When you're going to not use a water tank for a long period not only should you empty it, but you should dry it out. There are a couple of methods to do this. Then it's a case of a quick wash when you want to use it next. Leaving the water in the tank in a potentially warm, wet environment bacteria thrive and it can be a touch more challenging to clean depending on how the bacteria has spread. Even if you've reduced the water content by 98% you've reduced the area that bacteria can use.

And it means that you won't be tempted to drink it...
ok i think the trick is to keep using the boat!
 
I always use hot tub shock treatment. It is pure bleach (no horrid slimy additives), cheap and very effective. One scoop is more than adequate for even the largest of tank, run it through ALL the pipes and leave over night. Bleach and aluminium (if this is what your tanks are made of) is not a good combination on a regular basis, but for a one off shock perfect and does the job far better than any of the propriety products. It is safe as long as you thoroughly wash through and, in any event, potable in very low concentrations, and you can still tell if there is much left in the water after washing through. It really will kill everything and leave the pipes and tank clean of bacteria and fungus. If you get any smells after a while, give the system another shock, but usually after treatment it will good for six months. Obvioulsy it will not remove any sludge at the bottom of the tank, and if you can give the tanks a good flush as well so much the better. I shock my tanks a couple of times a year and dont get any smells even if the boat is left for a few weeks including in the Summer, which is the time any bacteria and fungus in the pipes will grow most rapidly. If you have hot showers, it is also worth (if you can) making sure they get properly hot. So many boats in my view have the thermostat turned down far too low, so the hot water never gets really hot. I appreciate you may need to be careful with children, but hopefully, you can always turn it down again.
 
Finally getting around to cleaning (if needed) the water tank and pipes on a new to me boat I recently bought. I've no reliable idea when it was last done and don't know what current water quality is like. There are some well old Aquaclear or such like tablets on board. Thinking of buying a water quality test kit to start with. Metal water tank, plastic pipes. Please, any advice out there? Would very much appreciate advice available. Thanks.
For ordinary cleaning Milton is the approved stuff. Soak tank and feed pipes for an hour with required dilution and flush through for bio security. However, look at the tank feed pipe and other places where crud can accumulate - a bit of bottle brushing with Milton may be advisable.

Then there's the taste test. With water from a good source, if there's still a residual taste, other than a hint of Milton, time for a more intensive clean. But see how you go - no need to dismantle lines before it's clear that is required.

Whale produce an inline filter that's easy to splice into the cold feed to the galley; this sees off all taste wrinkles etc. Costs about £24 pers season / filter replacement and is worth every penny. Enjoy your tea, without added flavours I say!

PWG
 
For ordinary cleaning Milton is the approved stuff. Soak tank and feed pipes for an hour with required dilution and flush through for bio security. However, look at the tank feed pipe and other places where crud can accumulate - a bit of bottle brushing with Milton may be advisable.

"Approved" by which recognised authorities? Milton is essentially very expensive, very dilute bleach in a fancy bottle. For cleaning, ordinary household bleach does exactly the same job for pennies. It's perfectly safe for cleaning water tanks.
 
Milton seems to contain a lot of common salt as well, and although we are talking about small amounts, I dont see the point of introducing salt to tanks. As we know it is very corrosive and would therefore seem best avoided as I cant see what purpose it serves.
 
Yes, there is quite a lot of research on the use of bleach and whether it has any detrimental effects on the body. Surprisngly perhaps it is for many dentists now the preferred treatment for irrigating root canals before further treatment up to about 5%. You can run your tanks with a very low concentration although I prefer to keep a seperate supply of water for drinking if you do that. Otherwise it keeps the water very clean and sweet smelling. There is some concern as I mentioned earlier that it can cause some issues with aluminium water tanks but I dont knwo at low concentrations how much of a concern this is. It certainly is a very powerful oxidising agent which is why it is so effective.
 
"Approved" by which recognised authorities? Milton is essentially very expensive, very dilute bleach in a fancy bottle. For cleaning, ordinary household bleach does exactly the same job for pennies. It's perfectly safe for cleaning water tanks.

Yes approved in the sense it's good for gear used to feed babies, so right for me. Anyone wishing to up the dose, for no good biological reason, is welcome to their opinion of course....there is private label Milton if pennies are the determining factor...

Oh, and do consult on the effects of chlorine......especially in higher concentrations.


PWG
 
Yes approved in the sense it's good for gear used to feed babies, so right for me. Anyone wishing to up the dose, for no good biological reason, is welcome to their opinion of course....there is private label Milton if pennies are the determining factor...

Oh, and do consult on the effects of chlorine......especially in higher concentrations.

Milton has made millions by trading on irrational fears of bleach. Used sensibly, bleach is perfectly safe and, as ip485 mentioned, is used by dentists.
 
Thanks all for the interesting and useful comments. Does anyone bother with or sea any use in bacteria testing kits? I sense why bother if one is going to shock doe the tanks anyway. It may be worth it if you don't know the water quality going in from the tap I would guess.
 
I think if you are going to use the tanks for drinking water, and have any doubt as to the source, something like the Nature Pure filter would make some additional sense,

I have read accounts that Legionella is a risk, especially combined with taking showers, hence my point about ensuring the hot water actually gets hot.

There are also UV sterilisers that can be installed for a few hundreds of pounds which are very effective.

However, I guess its about a proportionate response as to how far you go with these measures. If you are cruising in areas where the quality of the water is suspect then further precautions could be justified.
 
We are finally off to our boat in Spain Wednesday and one of my first jobs will be to clean the water tanks as they were left almost 11 months with water in them ? we don't drink from these types, it's purely for showering etc but I have no doubt they're going to be pretty nasty. They're plastic tanks (180l fore and 250l aft) so is the best method still to run the tanks to empty and then add thin bleach, fill tanks, leave for a few hours and then flush a few times? How much thin bleach will need to be added for this much water? Thanks all
 
Recc'd is teaspoon of Bleach per gallon of water. ..... with such solution - fill tank and leave for a reasonable period .. or if pushed for time try to leave for at least 10 - 15mins.
Pump enough through all pipes to have it exiting bleach solution - leave for a few minutes again so pipes and pumps etc. are sorted.
Pump out all and flush tanks / pipes IMHO at least 3 full volumes. That should be good to drinkable standard.

Me ? I have a box full of Army Sterilisation tabs designed for them to drop a tab in drinking bottle filled from stream etc. This time I dissolved a decent number of tabs in bottles and transfer to my on-board tank ... 70L (stainless steel), but I don't fill the tank completely - I let the fumes act on the air space, while the mixture acts on the lower part ... it stays there till boat launch when I pump all out and then do the 3x flush and rinse ...
Previously - I did the tablets day before putting boat back into service and pumped out once launched.

Each person has their own way ..
 
Thanks very much. So about 500ml thin bleach in total should do the trick. First task will be to find somewhere in Burriana that sells it! ?

A 'bleach' that I've seen in most countries I visit ... Clorox .....

Any cleaning plain bleach for floors ... washing machines .... etc. as long as its plain - is good to go. Just make sure of a good flush and rinse out after...

Its best to overflow if you can - to also rid the vapours / and filler pipes of the bleach.
 
Risk of frost.

Over here - we get down to -30C ..... even with a heater in the boat - difficult to heat tanks stuck away under bunks etc.

I left mine part filled with Sterilisation tabs in this winter .. part so vapours do their job and if it froze - the expansion wouldn't split the tank ... unlikely as its a hefty stainless steel job.
 
When I was pumping out the tank other day - I tasted the water and it was absolutely fine despite the months it sat in there. I also used the water to wash all the kitchen gear / plates / cups etc. instead of just pump and waste it.
 
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