Drinking water

milfordman

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My boat is a steel Ebbtide 33, and the water tank is built into the bottom of the boat several years ago it had started to rust . I treated it using international rubber tank paint Last year the water from it started to have black flakes in it. The flakes were very soft when you held them in your fingers, in fact you could not feel anything at all. The water had no unusual taste. However to be on the safe side we only used it for washing etc. We took our drinking water in plastic containers. Could anyone advise me as to what this might be? What would be the best action to cure problem?

Thanks in advance.
 
It sounds just like the muck that came out of my system! I tried putting a fairly strong solution of Miltons (baby bottle cleaner - bleach) through, but the tank in my case was OK, the pipes were growing this mould (?) in warm weather. In the end I replaced the pipework, brushing inside fittings , etc., and flushed again with Miltons. I am also told that a strong bicarbonate of soda soak and flush may clear it.
Good luck.
 
Sounds like either mould (organic growth in the tank) or possibly the rubber paint degrading (have you added a sterilising fluid at any time ?)

Try drying out the black flakes. If it's mould, then it is likely to be easily crumbled into fine powder; if rubber paint, then there will be a residue.

In either case, I start to be concerned about the tank walls losing structural and functional integrity.
 
I had a similar problem with a stainless steel tank, not rust but a very metalicy taste, tried sterilizing with milton but could'nt get rid of the taste, I have just fitted water filter (carbon/silver) made by Jabsco I think, hey presto! no more taste or smell. You should fit the filter as close to the tap as possible, you may still need to use sterilizer tabs for safety but you can't taste or smell them. Not quite the same problem I know but it worked for me.
Best of luck.

Old Al
 
This is a perennial problem and one of the reasons why people only ever drank beer on boats in years gone by. Sometimes progress isn't as useful as we are led to believe.......
 
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you may still need to use sterilizer tabs...

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Just use thin bleach.

You want between 10 and 20 ppm of Cl (a public swimming pool is about 10 ppm). Bleach is about 5%, so 20 ml of bleach is 1 ml Cl. There are about 1000 mg in 1 ml, so 20 ml of bleach gives 1000 mg Cl.

So, 20 ml of bleach in 100 litres of water is 1000 mg Cl per 100 litres, which is 10 mg/l or 10 ppm. This equates to one 5 ml dispensing spoon per 25 litres in the tank.
 
I know quite a few people who have had problems with steel tanks. one of them had a similar problem to you, about six months later, his tank started to leak. He ended up having a flexible tank of slightly smaller dimensions made, and put it inside the tank, the original steel tank protects the flexible one, and with the flexible tank there is no taint.

As for curing it before it gets this far, try miltons. bleach is good unless you have rubber fittins in the system, which bleach could damage. If it is an organic growth would a horticultural anti-fungal spray not do something to help?
 
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