Water tank

FlyingDutchman

FlyingDutchman

Well-Known Member
Joined
15 Dec 2004
Messages
842
Location
Amstelveen, the Netherlands
Visit site
As the water in our watertank smelled very nasty, I pumped it out yesterday and filled the tank (140 l) with fresh water. I also flushed the system with the freshly filled water. All seemed fine, but after 6 hours the smell was back again.
It is not a rotten egg smell, but something hard to define...
Any clues / remedies welcome!
 
Use sterilising solution such as Milton. Fill the tanks, leave overnight and then empty. Should kill anything - it will probably be bacteria, particularly in the pipes. Many people put a weak solution of Milton in the tanks to prevent bacteria. Does not affect the taste.
 
Any sterilising solution used for baby bottles will do I am sure there will be a Dutch equivalent. You can get proprietary cleaners from chandlers, but they will contain bleach in a similar way. Would not think it would do any harm to aluminium
 
What about the pipework? Clear hose is hopeless. The algae, crud and assorted wrigglers love the light. Only satisfactory solution is to replace the pipework with something like Speed Fit or Hep20

I've got this job to do on my manual water supply.
 
Is it a rigid tank or collapsible; the latter are alway worse especially when left almost empty as the surfaces stay damp & promote mould growth. As others say baby bottle steralising solution left in for a while - probably stronger than reccommended at least to start with. Or can you get PuraTabs or something similar.
 
The pipework is clear compressor type hose (the stuff with the woven-in threads) but it is not exposed to daylight? The tank is a rigid 140 liter aluminium tank.
I think I will try the Milton type fluid or tablets first as the replacement of the hoses is not easy. As with all things in boats they start building them around the parts you have to replace some time in the future!
 
We don't drink the water. Like you we use bottles for that.
But the water smeels so horrible, I don't even use it to wash my hands. The fact that the fresly tanked water had gone smelly after a couple of hours indicates that there is something wrong in the tank. Even after flushing the pipework it smells!
 
Is there an in-line filter and if so when was it last changed? My water system maintenance consists of waiting till till the water starts to smell slightly, and giving a dose of chemical treatment and replacing the filter. But I live aboard so the system never sits idle for any long period.
 
np.jpg


The best solution is a water purifier.
http://www.generalecologyeurope.com/naturepure.html
 
"Headmistress" used to post on here - Peggie someone. She knew all there is to know about boats water systems and loos. Try a search on her posts. I remember a very thorough solution to the problem you complain of - flushing tank + all pipes with diluted bleach (she gave concentrations, and Miltons is just diluted bleach, I think) then, as far as I remember, diluted vinegar to remove the taste, followed by a couple of rinses with water.

Good luck

Ali
 
To follow on from my last post - I saved Headmistress's instructions - here they are:

Not only your tank, but the whole system should be recommissioned....'cuz while 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 code covering electrical, plumbing, and heating of recreational vehicles. 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 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 (6% sodium Hypochlorine 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 by vehicle motion.

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.
 
Very interesting!
Many thanks for the information.
I don't want to install a water filter as I think the water should stay ok for a while and we don't use it for drinking anyway.
What puzzles me is what could be in the tank to make the water go smelly in such a short time?
I will try the procedure and see what the results are!
 
land yacht dealers do water sterilisation tablets designed to stay in and be drunk, you could try a few camping websites to find them.
 
Part of my job is sorting out ships and large yacht potable water systems.

Without lab testing your water or sniffing, even tasting, it is impossible to know what is causing the problem. You say it is not H2S - good. If eg. hydrocarbons -bad!

The cheapest way to go about this is to assume micro organisms are the culprit. DIY treatment will cost little, and has a good chance of success.

Let us assume your water system, as many yachts, has had years of neglect.

First, if you can get into the tank via a hatch give it a good scrub out with a bleach/water solution then pump it out.

You should then 'superchlorinate' the system (tank and plumbing) That means filling the tank with strongly chlorinated water, making sure it reaches the extremeties of the plumbing and allow time for it to do its job. (Officially that means 50 parts per million free chlorine for 24hrs) Then empty the system and fill with fresh, then empty the system and dose so as to have a concentration of 0.2 ppm free chlorine (the same as tap water). I recommend you dose at every fill thereafter.

The chemical additive commonly used on ships is subject to a £50 min order. I can put you in touch with the manufacturer but you may want to go for a cheaper option.

Using cheap supermarket own-brand (non scented) bleach, add enough to make a 50ppm concentration, then fill with water, run into the pipework and allow to stand for 24hrs. Remeber, the system should be closed to air or the Cl will 'breathe off' to atmosphere.

The calculation to achieve the 50ppm depends upon you knowing the volume of your tank. eg. if you buy bleach at 5% chlorine add 100ml to water for every 100 litres of tank volume.

For 0.2ppm dosing add up to 1ml every 100L tank vol.
 
simple solution: use Steradent. approx one tablet fot every 1000 L can be used to drink, if the tank is small, just put two tablets into a full tank, leave overnight then empty and refresh putting the right amount of Steradent into your tank according to size. Steradent has the same chemical composition as most water sterilising tablets but cost a fraction...

cheers
 
You must log in or register to reply here.

Share this page

Top