SailNet Community

SailNet Community (
-   Gear & Maintenance (
-   -   Cleaning a fresh water tank - how? (

jarcher 09-10-2008 06:37 PM

Cleaning a fresh water tank - how?
Hi All...

I now have my first boat that's not a dinghy and find that there is just tons and tons of stuff I don't know. Well I expected that, but here is a really simple thing that never occurred to me.

Today, I tried out the foot pump int he galley and it spit out brownish purple "water." I was able to locate the fresh water tank and it seems to be in for good.

So, how do I clean it?


mman30 09-10-2008 06:44 PM

The previous owner may have winterized the tank and used some kind of diluted anti-freeze, or the brownish stuff is just debris and god only knows what. I would try using regular house hold bleach mixture with water. let sit in the tank, and then flush it out with fresh water several times. If all you have is a foot pump (no mechanical pressure pump) you may want to see if you can access the top of the tank through a cap and wash clean the inside, and flush the water fill hose, and pump, and water lines. Thats my two cents.

mman30 09-10-2008 06:47 PM

And just as a precaution, I would check and make sure you did not access the holding tank. Brownish purple stuff that smells, You never know. LOL

jarcher 09-10-2008 06:56 PM

Thanks for the tip!

I'm sure this is the fresh water tank. Its under the cockpit astern, while the holding tank is under the vbirth next to the head! And of course I have a bunch of head related questions, but I'll save that for another thread.

I suppose running a bleach solution through it would kill stuff, but would it get the fill line and the top of the tank?

sailingdog 09-10-2008 06:57 PM

Bacteria/mold etc in the water tank can cause that... a heavy dose of bleach, and flushing the tank several times will help clear it. You should probably also follow up the bleach shock treatment with several tanks of fresh water and then one of water/vinegar and then several more of water.

Let the vinegar/water mixture sit, since it will help neutralize any odors in the system.

I would also recommend, if you have an access hatch, to scrub the water tank's innards and replace all of the hoses.

The bleach will kill most of the stuff in the deck fill hose and the top of the tank, if you fill it so that water is pouring out of the vent. :)

SteveInMD 09-10-2008 07:08 PM

I would rinse out a few times before adding the bleach. This is for a system with a pressure pump, but I'm sure you can adapt the procedure. It takes a lot of rinsing so you want want portable electric pump for this. You can get a 110 volt version at the hardware store for not too much money.

Turn water heater off at the breaker before beginning. Do not turn it
on again until entire recommissioning is complete.
1. Prepare a chlorine solution using one gallon of water and 1/2 cup
Clorox or Purex household bleach (5% sodium Hypochlorine solution ).
With tank empty, pour chlorine solution into tank. Use one gallon of
solution for each 5 gallons of tank capacity, which results in 4
Ounces of bleach for 10 gallons of water.
2. Complete filling of tank with fresh water. Turn on every faucet and
allow water to run until what's coming out smells strongly of bleach.
3. Turn off faucets--but do NOT turn off the must remain on
to keep the system pressurized so that the solution remains in the
lines. Allow to stand for at least 3 hours, but no longer than 24
4. Drain the tank through every faucet.
5. Refill tank with clean fresh water and drain again through every faucet.
6. 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
(iow, go sailing and tack a lot).
7. Drain tank again through every faucet, and refill with potable water.

jarcher 09-10-2008 07:28 PM

Thanks guys. If I can get into the tank I'll scrub it and if I can get to the hoses I'll replace them. Better safe than sick. I think I can get to all the hoses from the tank to the pump and faucet, but the fill hose may be tricky.

I did notice that the local ships store had a variety of hoses in stock, so at least I can find them.

If I can;t get to the tank, lots of bleach and viniger...

Thanks very much!

Lancer28 09-10-2008 07:56 PM

Hey - don't forget to change or installl an dunder-sink water filter from your local home depot. I think they only run $20 and HOLY COW what a difference they make!

I've tried the bleach (which works great) on my own boats, and I've tried the vinegar to follow up. The vinegar was FOUL even after flushing, and I had to replace some hoses. I even tried a baking soda / water solution which dissolved good but still didn't kill it all off.

Make sure you pump the bleach up to the pumps and unti it comes out of the faucets or else it will all be just sitting in the tank.

Do you have hot water or a recirculating system, or is it old-fashioned pump from seawater and freshwater tanks?

jarcher 09-10-2008 08:08 PM


Originally Posted by Lancer28 (Post 366489)
Hey - don't forget to change or installl an dunder-sink water filter from your local home depot. I think they only run $20 and HOLY COW what a difference they make!

That's a great idea, thanks!


Do you have hot water or a recirculating system, or is it old-fashioned pump from seawater and freshwater tanks?
Nothing that elaborate. I don't think there is a water heater at all. Just a tank with a fill hose running to the deck, and another hose running to a foot pump and from there to a faucet. Or maybe its better described as a nozzle.

The sink appears to drain to a fitting in the hull.

T37Chef 09-10-2008 08:12 PM

Our marina has a drive thu water tank cleaner, very simple to use, somewhat costly but works well. After the cleaning 10 illegals come over and wipe it down...awesome I tell you

All times are GMT -4. The time now is 04:13 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
User Alert System provided by Advanced User Tagging v3.1.0 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
(c) LLC 2000-2012

For the best viewing experience please update your browser to Google Chrome