Sailfree
Well-Known Member
Whats the best way to sterilise water tanks in say 1 week? Have 500ltrs of water spread over 3 tanks. Both Product and dilution factor recommendations please. Boat is 1 year old.
Thanks
Thanks
Sterilising Water Tanks
- Thread starter Sailfree
- Start date
Piers
Well-Known Member
Milton Fluid - and use the dilution on the label and fill the tanks. Leave for 24 hours having pumped it through all pipes and taps. Flush 2 or three times. No taste or smell is left. You can buy it in 1 ltr sizes.
steve_cronin
N/A
You won't actually "sterilise" it no matter what you do without risk of destroying it. The best most of us can do is to clean it to acceptable standards removing any nasty tastes or smells. (The next time you fill it you will be re-introducing organisms of all sorts anyway. It's a never ending battle) To this end give it a good soaking in any sodium hypochlorite cleaner such as Milton - rather expensive to buy the quantities required to be effective in a largeish boat tank in a reasonable span of time. Some use another oxidising agent such as hydrogen peroxide as this cannot leave a "public baths" whiff afterwards but this is going to be even more expensive than hypo.
I have used domestic bleach (not the thickened variety as this is too difficult to flush out) for a long time now without killing anybody or wrecking tank or machinery. A half bottle dropped in to a 180litre tank, topped up with water and left for a couple of hours before rinsing out three times and then more until it becomes potable, usually does the trick.
We keep our boat in the Med. and there, tank water is used for washing. We drink bottled water most of the time.
Steve Cronin
I have used domestic bleach (not the thickened variety as this is too difficult to flush out) for a long time now without killing anybody or wrecking tank or machinery. A half bottle dropped in to a 180litre tank, topped up with water and left for a couple of hours before rinsing out three times and then more until it becomes potable, usually does the trick.
We keep our boat in the Med. and there, tank water is used for washing. We drink bottled water most of the time.
Steve Cronin
VicS
Well-Known Member
Here we go again.
The resident Chemists do not approve of the use of domestic bleach because of the constituents, other than sodium hypochlorite, which may be OK for its intended uses ie bleaching laundry and cleaning drains, but maybe not so good for your health. It can also contain chlorates.......as in weed killer.
Milton contains only sodium chloride (salt) and sodium hypochlorite. Logically if it is safe for babies' bottles then it is going to be safe for drinking water tanks.
[ QUOTE ]
We drink bottled water most of the time.
[/ QUOTE ]
You might care to read this article which appears in the current issue of the Royal Society of Chemistry's "Chemistry World"
The resident Chemists do not approve of the use of domestic bleach because of the constituents, other than sodium hypochlorite, which may be OK for its intended uses ie bleaching laundry and cleaning drains, but maybe not so good for your health. It can also contain chlorates.......as in weed killer.
Milton contains only sodium chloride (salt) and sodium hypochlorite. Logically if it is safe for babies' bottles then it is going to be safe for drinking water tanks.
[ QUOTE ]
We drink bottled water most of the time.
[/ QUOTE ]
You might care to read this article which appears in the current issue of the Royal Society of Chemistry's "Chemistry World"
damo
Well-Known Member
Re: Sterilising Water Tanks - with filter?
I used the bleach method with some success, after a lot of flushing through. I removed the inline water filter before running the chlorinated water through it, just in case. Anyone know how highly chlorinated water would affect a filter, if at all?
I used the bleach method with some success, after a lot of flushing through. I removed the inline water filter before running the chlorinated water through it, just in case. Anyone know how highly chlorinated water would affect a filter, if at all?
marcusgillies
Well-Known Member
Re: Sterilising Water Tanks - with filter?
inline water filter!!!
Theres your answer fit one of these in the galley cold line and use this for drinking water, doesnt steralise the tank but steralises the water as you require it!!
inline water filter!!!
Theres your answer fit one of these in the galley cold line and use this for drinking water, doesnt steralise the tank but steralises the water as you require it!!
pvb
Well-Known Member
Bleach is fine...
As long as you use ordinary cheap household bleach (not the thickened stuff), bleach is absolutely fine for water tanks. I use Tesco Value own-brand bleach, which costs literally pennies a bottle.
The resident chemists might care to read this post by a well-qualified forumite, which apart from confirming that bleach is OK to use, also gives good recommendations on the dosage.
As long as you use ordinary cheap household bleach (not the thickened stuff), bleach is absolutely fine for water tanks. I use Tesco Value own-brand bleach, which costs literally pennies a bottle.
The resident chemists might care to read this post by a well-qualified forumite, which apart from confirming that bleach is OK to use, also gives good recommendations on the dosage.
damo
Well-Known Member
Re: Sterilising Water Tanks - with filter?
"doesnt steralise the tank but steralises the water as you require it!! "
No it didn't - there was still an unpleasant smell and taste (H2S) especially if the water had been standing for an hour or two. Same with a brand new filter. I think something was lurking in the pipes to the taps as well as further up the line.
"doesnt steralise the tank but steralises the water as you require it!! "
No it didn't - there was still an unpleasant smell and taste (H2S) especially if the water had been standing for an hour or two. Same with a brand new filter. I think something was lurking in the pipes to the taps as well as further up the line.
G
Guest
Guest
H2S .....
If you have H2S .... tell-tale smell is rotten eggs .... then you have a problem and better get if sorted. The Threshold limit for H2S is actually below the odour threshold and once smelt it deadens the sense of smell. It is a poison in vapour and dissolved form.
Sorry to frighten people .... get it sorted if you smell it.
Onto sterilising tanks .............. There are many Sterlising fluids .... branded and Shops own ... Milton is best known. You can also use common PLAIN thin liquid Bleach ....
Mix it and make sure you have that ozone'y sharp vapour with it .... pour it in partly diluted - it mixes better then ... and give it a real stir if possible or if not - a circulating pump is fine. The trick is to get it really stirred up and vapours produced .... The liquid will work on the tank and pipes ... the vapour on the upper surfaces etc.
Leave for 24 hrs.
If its possible after that to circulate through entire system and back to tank - that is fantastic ... if not then pump it through and empty back into tank. The idea to circulate it through the system more than once ....
Once you have completed maybe 2x the circulating .... pump out and discard liquid ....
You should then flush through with at least 3 changes of fresh-water .....
If its good enough for Babies - its good enough for us !!
If you have H2S .... tell-tale smell is rotten eggs .... then you have a problem and better get if sorted. The Threshold limit for H2S is actually below the odour threshold and once smelt it deadens the sense of smell. It is a poison in vapour and dissolved form.
Sorry to frighten people .... get it sorted if you smell it.
Onto sterilising tanks .............. There are many Sterlising fluids .... branded and Shops own ... Milton is best known. You can also use common PLAIN thin liquid Bleach ....
Mix it and make sure you have that ozone'y sharp vapour with it .... pour it in partly diluted - it mixes better then ... and give it a real stir if possible or if not - a circulating pump is fine. The trick is to get it really stirred up and vapours produced .... The liquid will work on the tank and pipes ... the vapour on the upper surfaces etc.
Leave for 24 hrs.
If its possible after that to circulate through entire system and back to tank - that is fantastic ... if not then pump it through and empty back into tank. The idea to circulate it through the system more than once ....
Once you have completed maybe 2x the circulating .... pump out and discard liquid ....
You should then flush through with at least 3 changes of fresh-water .....
If its good enough for Babies - its good enough for us !!
chrishalliom
New Member
I use beer line cleaner for all my sterilising, at home and on the boat, It's brilliant stuff, rinses easily, leaves no after taste and is only about £15 for a 5lt can. It's used everyday for cleaning beer lines without complaint.
damo
Well-Known Member
Re: H2S .....
"If you have H2S .... tell-tale smell is rotten eggs .... then you have a problem and better get if sorted. The Threshold limit for H2S is actually below the odour threshold and once smelt it deadens the sense of smell. It is a poison in vapour and dissolved form"
I have worked around wells in the Gulf, and have some idea of the physiology - I did the mandatory H2S courses, carried detectors and ran away from any wellheads that made a hissing noise! I would guess that there would have to be some pretty violent chemistry going on in a water pipe to give a hazardous exposure to H2S - or are you implying that the smell of some hard-boiled eggs could be dangerous? /forums/images/graemlins/wink.gif
"If you have H2S .... tell-tale smell is rotten eggs .... then you have a problem and better get if sorted. The Threshold limit for H2S is actually below the odour threshold and once smelt it deadens the sense of smell. It is a poison in vapour and dissolved form"
I have worked around wells in the Gulf, and have some idea of the physiology - I did the mandatory H2S courses, carried detectors and ran away from any wellheads that made a hissing noise! I would guess that there would have to be some pretty violent chemistry going on in a water pipe to give a hazardous exposure to H2S - or are you implying that the smell of some hard-boiled eggs could be dangerous? /forums/images/graemlins/wink.gif
HeadMistress
Well-Known Member
Re: H2S .....
Whatever you use to sanitize (sterilize is both impossible and unnecessary) your fresh water system, it's important to sanitize the plumbing as well as the tank...'cuz 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. So after you've put the solution in the tank, turn on the water pump, open every faucet on the boat--hot and cold--and let the water run till what's coming out smells strongly of chlorine. Turn off the faucets, but leave the pump on to keep the system pressurized so that the solution remains in the piping.
The recommended solution, btw, is a 5-7% solution of sodium hypochlorate in water...2 litres/50 gal of water tank capacity.
To get the job done, it should remain in the system for at least 3 hours, no longer than 24 hours.
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.
To remove excess chlorine taste or odor which might remain, prepare a solution of one litre white vinegar to five gallons water and allow this solution to agitate in tank for several days. 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.
Btw...it's VERY important any water heater be turned off at the breaker and not be turned on again until the entire recommissioning process is complete.
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. This method may also be used to sanitize a system that has become contaminated.
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.
Finally, you may not think you're ingesting your water if you don't actually drink it or cook with it...but you are. You wash your hands in it, then pick up a sandwich...wash your dishes and/or rinse out a cup with it, then pour your bottled water drink into the cup.
This method is NOT water purification, it only sanitizes the system. As long as you take on water that you know to be safe, the only issue is aesthetics--taste/smell that's unpleasant, but won't harm you. However, if you cruise to countries where water is suspect, water purification, not just sanitizing the system, is required.
Whatever you use to sanitize (sterilize is both impossible and unnecessary) your fresh water system, it's important to sanitize the plumbing as well as the tank...'cuz 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. So after you've put the solution in the tank, turn on the water pump, open every faucet on the boat--hot and cold--and let the water run till what's coming out smells strongly of chlorine. Turn off the faucets, but leave the pump on to keep the system pressurized so that the solution remains in the piping.
The recommended solution, btw, is a 5-7% solution of sodium hypochlorate in water...2 litres/50 gal of water tank capacity.
To get the job done, it should remain in the system for at least 3 hours, no longer than 24 hours.
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.
To remove excess chlorine taste or odor which might remain, prepare a solution of one litre white vinegar to five gallons water and allow this solution to agitate in tank for several days. 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.
Btw...it's VERY important any water heater be turned off at the breaker and not be turned on again until the entire recommissioning process is complete.
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. This method may also be used to sanitize a system that has become contaminated.
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.
Finally, you may not think you're ingesting your water if you don't actually drink it or cook with it...but you are. You wash your hands in it, then pick up a sandwich...wash your dishes and/or rinse out a cup with it, then pour your bottled water drink into the cup.
This method is NOT water purification, it only sanitizes the system. As long as you take on water that you know to be safe, the only issue is aesthetics--taste/smell that's unpleasant, but won't harm you. However, if you cruise to countries where water is suspect, water purification, not just sanitizing the system, is required.
VicS
Well-Known Member
Re: Bleach is fine...
[ QUOTE ]
The resident chemists might care to read this post by a well-qualified forumite
[/ QUOTE ]
This well qualified forumite, Alan Porter, is located in Canada where the domestic bleach may well be the same as in the USA where we established via Peggie Hall aka HeadMistress a while back it is free of the possible nasties that are in bleach in this country. His guidance on doseage is useful though.
I must confess that I have not yet got round to reading the label on cheaper brands of non thickened bleach.
I suppose one day I will also learn that nothing will persuade owners to deviate from the overiding compulsion to shave a few pence off the multi £k expenditure of owning a boat.
[ QUOTE ]
The resident chemists might care to read this post by a well-qualified forumite
[/ QUOTE ]
This well qualified forumite, Alan Porter, is located in Canada where the domestic bleach may well be the same as in the USA where we established via Peggie Hall aka HeadMistress a while back it is free of the possible nasties that are in bleach in this country. His guidance on doseage is useful though.
I must confess that I have not yet got round to reading the label on cheaper brands of non thickened bleach.
I suppose one day I will also learn that nothing will persuade owners to deviate from the overiding compulsion to shave a few pence off the multi £k expenditure of owning a boat.
G
Guest
Guest
Re: H2S ..... wasn\'t me that first said H2S ....
I wasn't trying to be rude ... and it wasn't me that first introduced H2S into the thread ....
If you do have experience of H2S - then you know what I mean ....
I am skeptical of H2S actually being in the water tank or pipes - as this is a derivative of Sulphur ... so am interested in its development / creation in the water system. I would hazard a guess that the smell is actually a Bacterial growth frequently found in water pipes especially carrying warm or tepid water ....
UK water having flourides and other bits in in it would be less prone to it unless left to stand for significant period and the flourides etc. have dissipated .... IMHO of course ....
I wasn't trying to be rude ... and it wasn't me that first introduced H2S into the thread ....
If you do have experience of H2S - then you know what I mean ....
I am skeptical of H2S actually being in the water tank or pipes - as this is a derivative of Sulphur ... so am interested in its development / creation in the water system. I would hazard a guess that the smell is actually a Bacterial growth frequently found in water pipes especially carrying warm or tepid water ....
UK water having flourides and other bits in in it would be less prone to it unless left to stand for significant period and the flourides etc. have dissipated .... IMHO of course ....
pvb
Well-Known Member
At only 14p a litre...
At only 14p a litre, I doubt that Tesco can afford to put anything much in their Value-brand thin household bleach apart from a sodium hypochlorite solution. Add to this the fact that the recommended dosage for water tanks is very small, and that several flushes with plain water are usually used as well, and it's very doubtful that any nasties would remain.
This is a "practical boat owner's" forum, and I for one don't think it's particularly practical to pour expensive branded bleach solutions like Milton down the drain, when a cheaper product is just as effective.
As regards the compulsion to shave a few pence off the cost of owning a boat, I confess I'm averse to paying over the odds for branded/advertised stuff when generic alternatives are available (eg Nurofen vs generic ibuprofen). Equally, I'm choosy about what I buy for the boat and I have some different ideas from most people on antifouling, etc. Not really cost-cutting, more avoiding wasting money. Which may be why I could afford a Hallberg Rassy in the first place.
At only 14p a litre, I doubt that Tesco can afford to put anything much in their Value-brand thin household bleach apart from a sodium hypochlorite solution. Add to this the fact that the recommended dosage for water tanks is very small, and that several flushes with plain water are usually used as well, and it's very doubtful that any nasties would remain.
This is a "practical boat owner's" forum, and I for one don't think it's particularly practical to pour expensive branded bleach solutions like Milton down the drain, when a cheaper product is just as effective.
As regards the compulsion to shave a few pence off the cost of owning a boat, I confess I'm averse to paying over the odds for branded/advertised stuff when generic alternatives are available (eg Nurofen vs generic ibuprofen). Equally, I'm choosy about what I buy for the boat and I have some different ideas from most people on antifouling, etc. Not really cost-cutting, more avoiding wasting money. Which may be why I could afford a Hallberg Rassy in the first place.
Stevie_T
Well-Known Member
Having no real knowledge on this subject I would personally use Milton or a less expensive alternative.
However just a thought, what about Sodium metabisulphate tablets as used in home wine making?
However just a thought, what about Sodium metabisulphate tablets as used in home wine making?
VicS
Well-Known Member
Yes sodium metabisulphite is another possibility. The sulphur dioxide it releases is not such a powerful sterilising agent as chlorine though. It is probably more expensive although the powder is almost cretain to be cheaper than the tablets.
Some people might find any traces of SO2 left in the water more unpleasant than Cl2.
Some people might find any traces of SO2 left in the water more unpleasant than Cl2.
VicS
Well-Known Member
Re: At only 14p a litre...
I really don't think that if I had bought two bottles of cheap domestic bleach in the past 28 years instead of the two bottles of expensive Milton I would have saved enough money to buy an HR instead of the Seawych.
I think you are just bragging about your HR and the fact that you can afford one. Go and show off your HR somewhere else and keep the PBO forum for exchanging practical advice.
I really don't think that if I had bought two bottles of cheap domestic bleach in the past 28 years instead of the two bottles of expensive Milton I would have saved enough money to buy an HR instead of the Seawych.
I think you are just bragging about your HR and the fact that you can afford one. Go and show off your HR somewhere else and keep the PBO forum for exchanging practical advice.
pvb
Well-Known Member
Brilliant...
That is a brilliant, funny, and illuminating post. If only everyone could keep up to your standards, Vic.
Seriously, I know from feedback that many people find that my contributions to this forum are, by and large, extremely practical and helpful. And if I wanted to brag about my trusty old HR, I'd mention it in my profile.
That is a brilliant, funny, and illuminating post. If only everyone could keep up to your standards, Vic.
Seriously, I know from feedback that many people find that my contributions to this forum are, by and large, extremely practical and helpful. And if I wanted to brag about my trusty old HR, I'd mention it in my profile.
robind
Well-Known Member
Re: Brilliant...
Get a gallon of white vinegar and chuck it in and fill the tanks up, Pump the system around and back to the tank through your filling hose and leave for a couple of days or as long as you can before you empty. then fill up and flush. the old methods are the best. I would fit a cheap wickes water filter too about £20.
Get a gallon of white vinegar and chuck it in and fill the tanks up, Pump the system around and back to the tank through your filling hose and leave for a couple of days or as long as you can before you empty. then fill up and flush. the old methods are the best. I would fit a cheap wickes water filter too about £20.