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Getting rid of fishy smell in water maker paper pre-filter ?

Sven

Seglare
We run the WM every 4-5 days. We either run it out in the open to make water, or we run the 5 gallons of product water we save through the WM just to keep the ceramic filter from getting messed up.

But what about the paper 10-µ filter ? It gets stinky just sitting there. We followed the Katadyn instructions and towed one filter behind us for 20 minutes while running the water maker through another, but it still has a slightly fishy smell.

Chlorine is a no-no according to Katadyn as it will demolish the ceramic filter, but is that true even if the chlorine has been rinsed out of the paper filter and then dried ?

How about vinegar or other chemicals ? I haven't tried making water with the still slightly smelly filter so I don't know if it is a non-problem but in a few days I won't be able to ask for advice again for a while :)



-Sven
 

toddster

Curator of Broken Parts
Blogs Author
Filters are always excellent habitats for bacteria. They will build up biofilms of mucus very quickly which will protect them from chlorine or any other sort of disinfectant. A particle filter can still be working, even with the biofilms in it. If odors are coming through into your finished water, you might try adding an activated carbon filter toward the end. I'm not sure how long it will last though. And/or adding multiple filters in series. The only other thing I can think of is letting it dry and exposing it to the sun, if possible, though that will undoubtedly cut down the filter life.

And nix on the vinegar. The kind of bacteria that eat that make enormous quantities of slime in the process of doing so.

Purely for academic information: The only way I've been able to dislodge bacteria from a (very expensive) filter unit was to recirculate 0.1% sodium pyrophosphate through it. This is the stuff that they're no longer allowed to use in laundry detergent. This unit had previously been stored in bleach, but when I ran the pyrophosphate through, it dissolved the biofilms and disgorged an opaque cloud of healthy bacteria and quite a zoo of protozoa, out of an allegedly "sterilized" filter.
 
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Sven

Seglare
Thanks for the reply.

Drying it out in the sun was another option I'd considered and I'll try.

I remember reading in Science News 15 years ago (or so) that researchers were surprised that pipes sterilized by running chlorine through them were still inhabited by slime protected bugs. At the time it was presented as a very surprising finding :)

The product water with a good pre-filter is wonderful. Just hope we don't have to keep throwing expensive filters at it. Rinsing out and drying the filter every use would also be a pain and I don't think making water even every day would solve the pre-filter issue.



-Sven
 

Guy Stevens

Moderator
Moderator
You can bleach them, but you have to rince them and the sun does help

chlorine will destroy the membrane filter if it is exposed to very much of it. (It isn't ceramic, that is a different type). However sodium hypo chloride (Bleach) is a easy to rinse out, and will evaporate if left in the sun.

The filters should also be material, and not paper. The paper ones will eventually break down and clog the membrane. I am going to assume that you have the correct material filters.

I recommend cleaning them by doing an initial rinse and clean in salt water and a gentle scrubbing with a very soft brush between the pleats. Then rinsing them in a diluted bleach solution in a plastic bucket for a few hours. Then we rinse twice in fresh water once overnight, and hang on the life lines in the sun for a afternoon for final drying and sun bleaching.

TSP (Tri Sodium Phosphate), which you can still by in powdered form at most hardware stores, does help in the cleaning process. as toddster stated above. We did occasionally use it in the initial cleaning in sea water.

That generally makes them clean, white again, and non smelly, having eliminated all the dead microscopic sea creatures out of the filters. We used three filters in about 4 primary filters in four years while out cruising if I recall correctly.

Another thing that helps a lot is that we ALWAYS flushed the unit every time that we used it with product water, I plumb mine so that the flush is through all components. So the filters get flushed with fresh water every use, this tends to discourage the growth of salt water based organisms in it too.

Guy
:)
 
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Sven

Seglare
Hi Guy,

Yes, we are only using the pre-filters that Katadyn specifies. Don't know if there are sources other than Katadyn brand ?

Post-flushing with product water sounds like a great idea, just a gallon or so I assume would do it. We keep 5 gallons for use in port to just run the WM every 4-5 days if we are in port or oily waters longer than that. I asked Katadyn if 5 gallons was enough (5 minutes run time) but haven't gotten an answer yet.

I wonder how the big RO outfits do it ? The ones that sell bottled water. Maybe they start with fresh water ?



-Sven
 

Sven

Seglare
Chlorine and membranes

Our cruising has developed a pattern. We make a hop, stay a couple of nights, or we stay weeks. We don't keep moving just to keep moving but rather try to enjoy the enjoyable places along the way.

This does present some water maker issues.

We'll avoid making water in areas with natural oil seepage, that's a lot of the southern California coast !

We also avoid making water in silty water like river deltas (or even estuaries).

So, how do we keep the water maker up to snuff without pickling ?

I asked Katadyn how much chlorine was enough to cause damage and the answer I got back (after the third time I asked) was that any chlorine at all was damaging. I was under the understanding that if you let chlorinated water stand the chlorine would break down or evaporate but the Katadyn reply seemed adamant that even if you could not smell any chlorine it would still be damaging if it had been added to the water.

So, we have bought RO water to run a gallon through the water maker every 4-7 days.

When you let tap water stand for a week so the chlorine won't kill your fresh water aquarium, does that mean the chlorine is "gone" ?

Are the Katadyn folks just overly cautious or can "old" tap water be run through the RO membrane once it is completely chlorine-smell free ?

We'd rather carry many gallons of clean salt water or even purchased water rather than pickling the membrane but it sure would be nice to know what the science is.



-Sven
 

Guy Stevens

Moderator
Moderator
chlorine evaporates rather rapidly

Chlorine is a highly reactive molecule, that will try to migrate from more concentration to less. If you are ever in an area that has chlorine in the city water, try this neat trick, run the water, and put a spoon under the stream so that it makes one of those cool fountain effects, you will immediately smell a lot of chlorine, it is leaving the water. A very high percentage of it leave the water at that point.

Soak them in a bleach water solution, then rinse them well (In a bucket for a day or so), and put them in the sun to dry, (The last step will also evaporate out any remaining chlorine). This generally takes care of the issue. Of course, it would be much better to sell you new ones and of course you can only use their brand... Yadda Yadda Yadda. Chlorine doesn't stick around, think about how much you have to add to the pool all the time!


If you are really worried about it go to the pool store closest to you and get a chlorine test kit. They detect even very small amounts of chlorine!

Also pickling isn't that bad. Find out what the real chemical is for that water maker. 90% of them, NOT Spectra!, use sodium metabisulfate for pickling. You can get it in 20 lb bags for less than a jar of it will cost you from the water maker makers....

Guy
:)
 
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Mr. Scarlett

Member III
There is a Little Wonder watermaker that came installed on our 35-2. To the best of my knowledge it has not been used in ~5 years. I removed it to reclaim over 50% of the port side storage in the saloon and have no plans to use it.
However, (let's assume it was a healthy, functioning unit until its last use), If I wanted to keep it "just in case", how would I go about storing it? If I wanted to sell it, how should I go about preparing it? In both scenarios is it just new filters and a membrane?
 
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