Cleaning a fresh water tank

[JSYmartini]

I have a fresh water tank in the bow, about 180 litres.
It has a clear plastic screw on hatch in the top but I've been unsuccessful in getting it open since I bought the boat.

So I've just made myself a steel tool that should fit the slot in the hatch with big handles so hopefully I'll get it this time round.

I've had a look through the hatch with a torch, it looks fairly clean inside although there's a few bits n bobs floating around.

I want to pump it out and give it a good clean but what with? I don't want to end up with funny tasting water or a bubble bath coming out of the galley taps.

I thought maybe Dettol surface cleanser - kills bacteria and viruses and allegedly leaves no odour?

Whats the standard procedure if there is one?

 

[essexboy]

Try Milton as in babies bottle cleaner, pour in Milton, then fill with water, and pump some through to clean pipe work leave for a couple of days, then flush through. You can also buy "Aquapur" from caravan shops, cheaper than swindleries ! Same method.

 

[nigelmercier]

I use Milton and leave it in, or bleach and flush out.

While you are there, look at the overflow hose.

 

[sueashforth]

I have use Milton myself in my tanks it does the job needs a few rinses afterwards had my tanks 30 years and I drink the water from them do this once a year

 

[prv]

I use powder from caravan shops; Puriclean I think is the name although I guess they're all similar. Generally a couple of doses (made up on the strong side of what it says on the label), each left overnight, then several flushes through. Essentially I keep flushing until the water no longer tastes chloriney; it ends up tasting just like it does from the tap at home and I'm quite happy drinking it.

Pete

 

[JSYmartini]

I've used tablets etc before, made the water taste horrible (specially in tea) and took ages to flush it out sufficiently.
I don't want to go down that road again, this is more just about manually cleaning the tank without affecting the water.

 

[JumbleDuck]

I use powder from caravan shops; Puriclean I think is the name although I guess they're all similar. Generally a couple of doses (made up on the strong side of what it says on the label), each left overnight, then several flushes through. Essentially I keep flushing until the water no longer tastes chloriney; it ends up tasting just like it does from the tap at home and I'm quite happy drinking it.

Same here. I find that the effects of a good Puriclean treatment last for several years. I reckon it needs about four rinses and a refill; any less and the water makes my lips go numb when I drink it.

 

[prv]

I reckon it needs about four rinses and a refill; any less and the water makes my lips go numb when I drink it.

Wow - numb lips sound scary!

I think I generally do about four flushes without even trying to taste it, then a couple more until it tastes untainted. This is a lot easier with an electric water pump than it used to be with Kindred Spirit's manual one (and manual sink-emptying pump)!

The instructions for Puriclean talk about adding a small dose to every tank fill. I don't do this, but it does mean that any small amounts left lurking in the system should be safe.

Pete

 

[Tranona]

I've used tablets etc before, made the water taste horrible (specially in tea) and took ages to flush it out sufficiently.
I don't want to go down that road again, this is more just about manually cleaning the tank without affecting the water.

Whatever you use is likely to have a bleach base so the tank will need rinsing in fresh water. Regular light dosing is the way to go and use bottled water for your tea and whisky if you don't like the taste of the tank water.

 

[Swanrad2]

I thought the SOP was - two thirds fill with water and Milton. Sail around a bit, leave the boat on a mooring for a bit longer - so the motion cleans the tank. Pump of and repeat.

 

[KellysEye]

I used to use a quarter cup of bleach for every forty gallons of water, run the taps to clean the pipes and leave it for 24 hours then flush twice. But that's for smelly water which you haven't mentioned. So if you pump all the water out and check the bits are in it and replace it that should do what you want bleach being optional.

 

[rob2]

My method for cleaning is considered unusual by some. If you want to get any solids out, you really need a good flow of water out of it, so I unhook the outlet and let it flow into the bilges. Of course, I give the bilges a scrub with a little detergent beforehand, so that the sluicing with fresh water rinses it all and then its much quicker to remove using the bilge pump. Cold water tends to kill off any foam, so you don't get your legs soaped up! Refit the outlet pipe (or maybe replace periodically as they can hold contamination in the dark, warmer conditions) and treat the tank and pipes with Miltons. Flush again then refill. You shouldn't get any chlorine aftertaste so long as enough is flushed through the pipes or new ones are fitted.

Rob.

 

[markhomer]

Silver Stabilised Hydrogen Peroxide

best there is , use as bleach , but far more effective , pump it through your system and it will clean out all , removes biofilm where bleaches performance is poor , bio film is the slime you see in old pipes and food for bacteria , legionella , you name it .you can (should ) even leave a maintenance dose in tank which will keep your water safe . has no taste or smell and perfectly safe to drink at effective doses , I use it commercial on domestic water tanks and systems , from 50 ltr tanks to my biggest 160,000 ltrs , it has proven its self effective to me for nearly a decade in commercial use .

it gives of a misty vapour (hydrogen /oxygen) as it kills off bacteria , when this stops you know you are clean . (not enough to cause explosion risk , i was initially concerned fist time I used on tank with dead pigeons etc , which bubbled like a pot of soup - prior to tanks being drained and scrapped , this was to make water safe for poor souls working with it ! )

I have often thought about offering a service to private individuals , but , hard market compared to commercial .


You should also consider treating your water that you take aboard , you never know whats in it and your putting it into a worst case scenario .

Ive seen products in chandelrys with hydrogen peroxide products and would thoroughly recommend , cant express how good and something you should do .

after treatment water tastes so good you can put in a dram , or god forbid a cup o tea .


by the way I used bleach for many years before moving to Hydrogen Peroxide which has transformed my business , i can see no use for bleach and would only use IF insisted upon by customer , never happened yet . advantages 1. Far superior performance ,proven scientifically , far less harmfull to handle in equivalent doses , bleach will take your eye out at 2% , no taste or smell with treated water , you can taste down to less than 2 ppm (parts per million bleach ) this around the level when you smell and taste at home when waterboard has been dosing , max allowed level for drinking .If you want no taste , smell with bleach you must balance out with more chemicals -- sodium thiosulphate . With stabilised Silver Hydrogen Peroxide , all you putting in is hydrogen and oxygen , silver in infitessimal small dose , remember rich folks used silver plates and cutlery because of anti bacterial properties too .


If you must use bleach to carry out a disinfection as per british standards you are seeking to maintain a level of 50 ppm for 1 hour , note doseage requirement is dependant on ph level of water and maintaining may require topping up as you go and chlorine used up .dont expect this to go any deeper than the surface layer of any biofilm you have in your system .

 

[VicS]

Milton and bleach mentioned a couple of times above but without any firm recommendations on concentrations

The recommended dose for sterilising a tank with Milton fluid is 30ml per 5 litres. Allow to soak for 15 minutes and then rinse out.

For sterilising drinking water 2.5ml per 5 litres.
If you don't exceed this you should not have any trouble with foul tasting tea.


For a large tank 30ml/ 5litre can be quite a lot of Milton. If you therefore use bleach use a thin one which does not contain any detergents or thickeners and because it contains about 2.5 times the hypochlorite concentration as Milton use only about 12 ml/5litre.