Water filters

pcatterall said:
Am giving this matter serious consideration.
I cant find the recent PBO article even though I have all the recent Mags ( but September missing!)
I have a 100 gallon water tank and now we are in warmer climes find the water is not tasting too good ( despite washing and flushing the tank) I had thought to use chemical treatment to make the water safe then a small filter to get rid of the chemical taste!! ( one of the PBO suggestions I think).
The alternative would seem to be a more expensive filter which would purify and get rid of any taste. ( about £300) I think.
I am also considering installing a hand pumped tap with a small filter just for drinking water.
I will appreciate your suggestions and any help in finding that darned article!!
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The solution that I would recommend without hesitation, assuming that you are cruising afar, is a Nature Pure type filter with the tap at the galley. If you need greater volume then consider another General Ecology product such as the Seagull model. High quality output at approx. £45 per filter which lasts us nine months of each year of warm water cruising. The bliss of no more carting and storing of dodgy bottled water and that terrible chemical taste in the tea!! The wife considers ours the best thing that we have ever bought for the boat.
 
oldvarnish said:
This from the General Ecology website: "physically removes disease bacteria, pathogenic cysts, and other specific parasites down to 0.1 microns.'

Then this from an American Public Heath site:

A microfiltration filter has a pore size of approximately 0.1 micron (pore size ranges vary by filter from 0.05 micron to 5 micron);
Microfiltration has a very high effectiveness in removing protozoa (for example, Cryptosporidium, Giardia);
Microfiltration has a moderate effectiveness in removing bacteria (for example, Campylobacter, Salmonella, Shigella, E. coli);
Microfiltration is not effective in removing viruses (for example, Enteric, Hepatitis A, Norovirus, Rotavirus);
Microfiltration is not effective in removing chemicals.

So viruses not removed, but 'probably' most bacteria.

Why not get bottled water delivered to the boat? Have you tried persuading Tesco to deliver 500 miles offshore?
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well have a look on here, unless your micro filtration system is a membrane rather than a fibrous media (membranes need a pump) so yours is certainly a fibrous media, you will struggle to get anywhere close the results you list above.

http://www.millipore.com/membrane/flx4/filtration_basics_hm&tab1=3&tab3=1#tab1=3:tab3=1

"Why not get bottled water delivered to the boat? Have you tried persuading Tesco to deliver 500 miles offshore?"

Its called passage planning; ie plan how much you need before you set off and get it delivered :-).
 
Marsupial said:
"Why not get bottled water delivered to the boat? Have you tried persuading Tesco to deliver 500 miles offshore?"

Its called passage planning; ie plan how much you need before you set off and get it delivered :-).
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Oh, thanks. I'm much in need of such passage planning advice being a bit of a beginner. Can't imagine why I hadn't thought of that.
 
oldvarnish said:
Oh, thanks. I'm much in need of such passage planning advice being a bit of a beginner. Can't imagine why I hadn't thought of that.
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rofl-smiley-gif-800.gif
 
Water treatment

pcatterall said:
Am giving this matter serious consideration.
I cant find the recent PBO article even though I have all the recent Mags ( but September missing!)
I have a 100 gallon water tank and now we are in warmer climes find the water is not tasting too good ( despite washing and flushing the tank) I had thought to use chemical treatment to make the water safe then a small filter to get rid of the chemical taste!! ( one of the PBO suggestions I think).
The alternative would seem to be a more expensive filter which would purify and get rid of any taste. ( about £300) I think.
I am also considering installing a hand pumped tap with a small filter just for drinking water.
I will appreciate your suggestions and any help in finding that darned article!!
Click to expand...

We use Aquasol cleantabs with some success, see here, http://www.cleantabs.co.uk/aquacleantabs.htm

We also have a Jabsco filter in the water line and change that every year. Well, we change it when it stops working, every other year.
 
Boat marina based, steady throughput of water...some may say excessive, but women insist on washing and water sourced from British/French supplies I find that an online Whale filter and an occasional dose of Milton keeps the water sweet.

I suspect that given hot conditions and uncertain water quality it wouldn't be man enough for the job.
 
ghostlymoron said:
Old Varnish, What did you do on your long distance cruise. Start out with enough or replenish with rain?
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Exactly that. I don't have a lot of tankage, but with just one person on board it makes things easier. I made a rain-catcher which I tied to the end of the boom and that did good service. But it's surprising how little it rains in parts of the Atlantic.

I had a small water-maker, a Katadyn 40, which only uses 4 amps, and in the tropics that was more than made up for by the excess power coming from the solar panels. But it only produces 1/2 gallon per hour so I used it more as a 'keep the kettle full' device than a 'nice long shower everyday' bit of kit.
 
oldvarnish said:
I've got a Jabsco filter as well on the galley tap ( The Pure has it's own tap).

The Jabsco are fine in most situations. But in parts of the world where water is a little more suspect, then you need something more like a Pure to get the finest possible filtration. For example, the Pure claims to filter out viruses - I don't think the Jabsco would do that.
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to be far we only filled up from know good soureces. The rest of the time we used a watermaker so filtration was only really dealing with taste and anything that was already in the tank. The water does taste good though. I will probably do the same next time we do a lap of the Atlantic
 
Marsupial said:
well have a look on here, unless your micro filtration system is a membrane rather than a fibrous media (membranes need a pump) so yours is certainly a fibrous media, you will struggle to get anywhere close the results you list above.

http://www.millipore.com/membrane/flx4/filtration_basics_hm&tab1=3&tab3=1#tab1=3:tab3=1
Click to expand...

Well, I took your advice and looked at the millipore site. What I found there was a graph shoeing that a fibrous media microfilter would remove many bacteria but not be at all effective against viruses, which is exactly what Old Varnish told us. The millipore site is a bit inconsistent as the graph gives a range from 0.07 to 10 microns for microfiltration, whereas the text states 0.05to 5.0 microns for the same function. What is clear is that fibrous media filters extend well into the microfiltration region (down to 0.75 microns) and well into the size range for bacteria (0.35 - 9.0 microns).

From my own experience, 1.0 micron (guaranteed max particle size passing) fibrous media filters are commonly used in industrial processes, and they don't need the immense pressure differences required to get a liquid through a semi-permeable membrane, such as in reverse osmosis.

The General Ecology website claims 0.4 microns absolute for their Seagull filters. While I generally treat manufacturers' claims with a large pinch of salt, they back this up with test data obtained by the US EPA, so I am inclined to trust it.

I have no interest in any of these suppliers, not even as a customer, yet!
 
Thanks everyone. Very interesting. I think that I will go the route of adding purifier when I refill the tank and fitting a Jabsco filter to remove the taste.
I still haven't found the September issue of PBO so can anyone remember which purifier they recommended!!
Thanks again
 
PeterWright said:
Well, I took your advice and looked at the millipore site. What I found there was a graph shoeing that a fibrous media microfilter would remove many bacteria but not be at all effective against viruses, which is exactly what Old Varnish told us. The millipore site is a bit inconsistent as the graph gives a range from 0.07 to 10 microns for microfiltration, whereas the text states 0.05to 5.0 microns for the same function. What is clear is that fibrous media filters extend well into the microfiltration region (down to 0.75 microns) and well into the size range for bacteria (0.35 - 9.0 microns).

From my own experience, 1.0 micron (guaranteed max particle size passing) fibrous media filters are commonly used in industrial processes, and they don't need the immense pressure differences required to get a liquid through a semi-permeable membrane, such as in reverse osmosis.

The General Ecology website claims 0.4 microns absolute for their Seagull filters. While I generally treat manufacturers' claims with a large pinch of salt, they back this up with test data obtained by the US EPA, so I am inclined to trust it.

I have no interest in any of these suppliers, not even as a customer, yet!
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Peter,

I hear you, but I don't think you hear me. I have an RO system running at 0.1nm against the best microfiltration systems running at 50nm and wouldn't consider drinking the product without further treatment why?

a few quotes for you consider


" "Particle filtration" removes particles of 1 micrometre (3.9×10−5 in) or larger. Microfiltration removes particles of 50 nm or larger. Ultrafiltration removes particles of roughly 3 nm or larger. "Nanofiltration" removes particles of 1 nm or larger. Reverse osmosis is in the final category of membrane filtration, "hyperfiltration", and removes particles larger than 0.1 nm."

"a fraction of the living bacteria can and do pass through RO membranes"

I'll say it again - your choice
 
pcatterall said:
Thanks everyone. Very interesting. I think that I will go the route of adding purifier when I refill the tank and fitting a Jabsco filter to remove the taste.
I still haven't found the September issue of PBO so can anyone remember which purifier they recommended!!
Thanks again
Click to expand...

The best one was the General Ecology seagull IV. It was also the most expensive.
 
As previously stated, the Jabsco Aquafilta, and any of the other activated carbon filters are only designed to reduce the taste of chlorine and other types of sterilisers (eg Milton) from the water. They are NOT water purifiers, and bacterial microbes could still get through. Going from memory, I'm sure that we wrote that in the data booklet supplied with the Aquafilta. With clean water though, the difference once an activated carbon filter is fitted is large - very similar, to the Britas filter, I use at home to improve the taste of tap water.

For best results, I would use a good RO unit, with an Aquafilta after it, however, I have little knowledge on RO units other than test results read in the yachting mags!

With any carbon activated filters, you do need to change the cartridge at least once a year, as stagnant water uses it's cleansing properties, as much as water flowing through the unit....

Jon
 
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