Cleaning water tank

steve350

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I'm seeking advice on the best way to clean the pipes and flexible plastic water tank on my boat. There seems to be some fungal growth inside the supply pipe and I guess inside the tank as well. Are any products available that would clean it up, sterilize it? Ideally I'd like to pour a cleaning agent into the water inlet, flush it through with fresh water and Bingo, it's done!
 
I've used Milton sterilising 'fizzy' tablets before (they come in stips of aluminium foil)... I put about 15 tablets in a full up 80 litre tank and left it overnight... completely drain, refill, drain and then refill... no aftertaste.
 
Or plain bleach - diluted well down of course.

Sterilising fluid / tablets for beer kits.

Note that most sterilising agents have vapours that also sterlise as well as the fluid itself. Read instructions of beer sterlise kits as example and they advise to leave standing for reasonable time up to 24 hrs ... in which vapour and fluid will act.
Drain through lines and tap ... down through overboard of sink - you get to clean whole system ... refill ... drain of again ... refill and drain of again ...

I do my tank / system at start of each season now. Never a prob.
 
I have not found either bleach or Milton to be very effective where there is obvious growth of organisms in the pipes or tank. Physical cleaning is best in the tank with a small amount of detergent. A toilet brush (new!) is good for getting into far corners, on an extension if needed.

Once reasonably clean, visit a caravan shop. Nowadays there are some quite aggressive products that are intended for more serious water system cleaning jobs. I haven't yet used one but I will this spring. Some come as two packs, an initial aggressive one and then a milder, neutralising dose.
 
once you're got 'bits' growing in there you need something more aggressive - I've had success with the stuff sold to clean and sterilise brewing equipment - Brewmakers 'Bruclens' cheap and works well. Just don;'t leave it in too long as I doubt if it does the seals etc much good..
 
If you were a ship, or commercial yacht I'd require you to super-chlorinate the tank and entire pipework. Best if you could get in there with a scrubbung brush. Then you'd maintain the water quality with good hygiene on filling and dosing at every fill.

Do you know the volume of your tank(s)?

The product I prefer to use is Instachlor. You may be able to purchase it locally. Speak to the company techie on the phone and explain what you are doing. Be guided by them.

Or, and this has been mentioned already, buy the cheapest thin supermarket bleach (non perfumed). Get your calculator out and pour in to the empty tank enough bleach to give at least 50ppm when you fill with fresh water. Make sure this 50ppm water is into all the pipework by running the taps a little.

Allow to stand for 24hrs.

Then, if you are lucky you can drop the contents into the bilge and then over the side with the high volume bilge pump. If not lucky pump it out through the galley sink.

Flush tank.

Dose for 0.2ppm free chlorine (in my experience aim for 0.5ppm. It'll end up around 0.2. Easy with Instachlor, more diff with bleach)

0.2 by the way is the same as tap water and the chlorine is just detectable by most humans taste when compared against mineral water.

Get it badly wrong and it will taste like a swimming pool and your crew will mutiny /forums/images/graemlins/smile.gif

Best of luck

ps In this port we sample the free chlorine and test for bugs on request - all for free /forums/images/graemlins/cool.gif
 
The same company I think used to have a 'inservice' product called something like Instapure ... tablets that you could use when camping / away from your normal home supply. To sterilise any water you used to prevent Montezumas Revenge.

I can't get Miltons or similar out here - so I use plain bleach.
 
Many thanks for all the suggestions. Hopefully I can clean the system without having to do any scrubbing as access to some of the pipework and fittings is severely restricted.
 
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