We bought a boat that has been well maintained but little used. The water from the fresh water tanks has a strong musty smell. We have two 500 gallon tanks. Should we simply drain the tanks and refill them or should we try to clean the tanks somehow?
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Personally, I like to use a 2 liter bottle of cheap Vodka which spends the winter in our 30 gallon(?) water tank. A waste of good, cheap hooch to some but it is great for cleaning your hands in the spring.
Your tanks are HUGE by comparison so I would guess it is a nearly 50' boat. Too big to waste that much Vodka on. I would suggest filling each tank partially and then pouring in an appropriate amount of bleach, let it stay in there for a few days while you take the boat out, then drain, rinse and refill with fresh water. If it is still musty smelling then repeat.
I am not sure about the proportions but most municipal water systems have some bleach (sodium hypochlorite) in their water as a treatment for germs. I am fairly certain that in municipal water the percentage is well below .01%.
I would guess that 1 quart of bleach in 200 gallons of water (< .125%) would be pretty strong for drinking but might do the trick for cleaning out the tanks.
This from Wikipedia (if you can believe them):
"Sodium hypochlorite has been used for the disinfection of drinking water. A concentration equivalent to about 1 liter of household bleach per 4000 liters of water is used. The exact amount required depends on the water chemistry, temperature, contact time, and presence or absence of sediment. In large-scale applications, residual chlorine is measured to titrate the proper dosing rate. For emergency disinfection, the United States Environmental Protection Agency recommends the use of 2 drops of 5%ac household bleach per litre of water. If the treated water doesn't smell of bleach, 2 more drops are to be added."
Source: http://en.wikipedia.org/wiki/Sodium_hypochlorite
So 1:4000 is what is used in municipal water supplies which is about a % 0.025 solution of bleach to water. 1 pint of bleach mixed with 100 gallons of water would be a 1:1600 ratio of % 0.0625.
I hope that someone with municipal water supply experience chimes in but I think you get the idea. It is important to rinse out your tanks once you have shocked them with a high concentration of bleach (sodium hypochlorite).
My best.
Your tanks are HUGE by comparison so I would guess it is a nearly 50' boat. Too big to waste that much Vodka on. I would suggest filling each tank partially and then pouring in an appropriate amount of bleach, let it stay in there for a few days while you take the boat out, then drain, rinse and refill with fresh water. If it is still musty smelling then repeat.
I am not sure about the proportions but most municipal water systems have some bleach (sodium hypochlorite) in their water as a treatment for germs. I am fairly certain that in municipal water the percentage is well below .01%.
I would guess that 1 quart of bleach in 200 gallons of water (< .125%) would be pretty strong for drinking but might do the trick for cleaning out the tanks.
This from Wikipedia (if you can believe them):
"Sodium hypochlorite has been used for the disinfection of drinking water. A concentration equivalent to about 1 liter of household bleach per 4000 liters of water is used. The exact amount required depends on the water chemistry, temperature, contact time, and presence or absence of sediment. In large-scale applications, residual chlorine is measured to titrate the proper dosing rate. For emergency disinfection, the United States Environmental Protection Agency recommends the use of 2 drops of 5%ac household bleach per litre of water. If the treated water doesn't smell of bleach, 2 more drops are to be added."
Source: http://en.wikipedia.org/wiki/Sodium_hypochlorite
So 1:4000 is what is used in municipal water supplies which is about a % 0.025 solution of bleach to water. 1 pint of bleach mixed with 100 gallons of water would be a 1:1600 ratio of % 0.0625.
I hope that someone with municipal water supply experience chimes in but I think you get the idea. It is important to rinse out your tanks once you have shocked them with a high concentration of bleach (sodium hypochlorite).
My best.
Do a search on the word recommission and you can find Peggie Hall's recipe for cleaning water systems.
Thanks, I found Peggy's instructions.
Her instructions answered my questions. She also recently helped me with the installation of an electric toilet and waste treatment system.
I nominate Peggy for the Cruiser's Hall of Fame (if there is one).
Her instructions answered my questions. She also recently helped me with the installation of an electric toilet and waste treatment system.
I nominate Peggy for the Cruiser's Hall of Fame (if there is one).
I think this was a Peggy reply:
CLEANING THE WATER SYSTEM
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. 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. Before beginning, turn off hot water heater at the breaker; do not turn it on again until the entire recommissioning is complete.
1. Fill the tank with 1 quart Clorox household bleach per 50 gallons of water.
2. Open every faucet on the boat and let water run till what's coming out smells strongly of bleach. Then close all faucets, but 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 distilled white vinegar to five gallons water and allow this solution to agitate in tank for several days by vehicle motion. If the bleach has been thoroughly flushed out of the system, it is not necessary to fill the tank more than 1/3 full.
6. Drain tank again through every faucet, and flush the lines again by filling the tank 1/4-1/2 full with potable water...drain again and fill tank for use. This will remove all antifreeze taste/odor.
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 recommissioning the system, and that filters require regular inspection and cleaning or replacement.
CLEANING THE WATER SYSTEM
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. 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. Before beginning, turn off hot water heater at the breaker; do not turn it on again until the entire recommissioning is complete.
1. Fill the tank with 1 quart Clorox household bleach per 50 gallons of water.
2. Open every faucet on the boat and let water run till what's coming out smells strongly of bleach. Then close all faucets, but 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 distilled white vinegar to five gallons water and allow this solution to agitate in tank for several days by vehicle motion. If the bleach has been thoroughly flushed out of the system, it is not necessary to fill the tank more than 1/3 full.
6. Drain tank again through every faucet, and flush the lines again by filling the tank 1/4-1/2 full with potable water...drain again and fill tank for use. This will remove all antifreeze taste/odor.
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 recommissioning the system, and that filters require regular inspection and cleaning or replacement.
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