"sweetening"water tanks

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Senior Member
Jun 28, 2008
Does anyone have a method for sweetening fresh water tanks?* The history of my boat is that it spent about 10 years on the Great Lakes (Michigan), and was laid up annually.* I don't know the exact history of the winter layups, so I don't know if the tanks were drained during these periods.* The water has a very heavy mineral taste.* I have tried the chlorine flush method of emptying the tanks, adding bleach, filling the tanks, running water lines, and draining tanks after an overnight period.* This has produced some limited success,* but the water still has a heavy taste.

Any ideas would be appreciated.
I've read that dissolving baking soda in water and then adding it to the tank will help. You don't leave that solution in there. Let it soak then pump it out like you did with the bleach solution. I don't know what concentration to use though. There also some commercial products out there at the boat stores you could try. If you've done the bleach thing, it's probably sanitary.
Red, What does a heavy taste mean? The water coming out of your tank is not going to taste like the water from your faucets at home. In addition you need to look at the source of the water you are filling the tanks with as well as something as simple as the hose you are using to fill the tanks. As stated there are additives that can be purchased at ant RV supply to improve the taste of the water. Use a charcoal filter at least when filling the tank. Chuck.
Common on laid up boats the water looses the chlorene , and gets gamey.

The only solution is to fill with a heavy chlorene concentration and then flush a few times.

Baking soda can improve the water taste and should be used for the last flush , give it an hour or two to absorb any taste.

The entire system , not just the tanks need the chlorox so run till every faucet hot and cold is chlorox stinky , and disconnect the ice maker and do its feed too.

Some will leave the chlorene in fot an hour , I prefer overnight.

When going over the system be sure to look for clear plastic tubing and DISCARD it.

The smallest git of light will get thru the clear plastic and encourages the growth of green slyme in the tanks or tubing.

On a new build our preference is for 5/8 copper tubing with FLAIR fittings.

A good refrigeration grade (not NAPA) flair tool is under $50 and will last a lifetime Imperial is a brand.

The flair fittings are more expensive than rubber hose or solder fittings , but the ability to carry a bit of tubing and repair the system in place , with no torch , no local "potable" water hose will pay for the fittings cost on the first freeze , or errant toolbox damage.

Thanks for the advice, all. I've tried the bleach, and am pretty careful about tasting the water before it goes in the tank. I think I'll try the baking soda idea for staters.

I also "found" a hose in the engine room - clear plastic that terminates in a ball valve; I think it was installed by the PO to top off engine water, so I'll work on replacing that - thanks FF for the idea.
How bout a couple of gallons of rum, then add some limejuice and pitch a big marina party to empty the tanks!
Nice idea Steve,

Lets see, 160 gallon water tanks, so say a barrell of rum? I could manage that, but then I got to thinking about trying to squeeze all those tiny little limes y'all have down there...makes me tired thinking about it.
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