Bacterial Water Filtration Necessary?

[Labatt]

Hi All -

We're primarily cruising the US East Coast, the Bahamas and the Caribbean. If we put some bleach in our tanks each time we fill them and use a charcoal filter on our tap water, is there a need to use any other filtration system? I was looking at a couple of 3M systems, but we'd prefer not to take up the space (2 adults and 2 kids on a Passport 40) if we don't have to. I'd like to skip ANY filtration systems except for the charcoal filter if at all possible. We do not have a watermaker - any water we use will be dock fill or land fill into our jerrycans. Should this decision change if we decided to go farther south (DR, Central/South America, etc.)? I'd like to hear the "in reality" answers vs. the "this is what everyone says" answers if at all possible

Thanks!

Chris
s/v/ Pelican
s/v Pelican - Following A Dream

[hellosailor]

Chris, bleach works. I'm told there is some chlorine-resistant giardia out there now, so you may want to use doses that are on the high side of recommendations. Or consider using iodine (crystals or tincture) as an alternative.

Another option would be to add a UV-C treatment lamp inline before your tap, or place one in your tank. UV-C breaks down all living tissue, including bacteria and viruses, and is used in commercial sterilizing systems.

[MarkJ]

We use Star brite Water conditioner.
In the Caribbean it was $4 for 4.5oz / 130 grams where 1 teaspoon (5g) treats 400 litres / 100 gallons!

I dunno if it kills bugs but I doubt you would need anything in the USa / Caribbeean as the water in both places is fine.

We have been told not to drink the water everywhere but its been fine, great, fantastic and superb. Just more scare tactics trying to keep you at home in a pad of fluffy cotton wool.

Mark

PS We haven't seen any bodies of dead cruisers hanging onto water taps.....

[donradcliffe]

We never treat our tanks, but have a one-micron rated charcoal filter (seagull) on our drinking water. Never a problem with illness or taste.

[Hud3]

Ditto what donradcliffe said. The Seagull IV or equivalent for filtering just the water that you drink is a great addition to a cruising boat.

[David M]

Wikipedia says some bacteria can be as small as 0.5 micron. I don't know though if you want to drink water which chemically has been treated for bacteria since there is beneficial bacteria that aids in the digestion of your food. In that respect, it may be better for your health to filter than to chemically treat.

Perhaps something like one of those Brita filters which attaches to the end of your spigot filters down to half a micron? I know for a fact you can buy inline scientific grade filters that filter at whatever micron level you want. I have no idea what they cost. It may be worth looking into.

Bacteria - Wikipedia, the free encyclopedia

[maxingout]

We sailed around the world without any filter in our water system once it was on board. We occasionally used a sediment prefilter when taking water on board at a dock through a hose. After the rains in the Marquesas of French Polynesia, sediment gets into the water supply. During our circumnavigation we put a couple of tablespoons of bleach into our water tanks maybe ten times in eleven years if there was any reason for concern.

[John Drake]

Bleach is commonly used to disinfect water around the world, including the US, obviously. If you use bleach, you should use it in specific concentrations and not add willy nilly.

That said, bleach in your fresh water system aboard can degrade certain plastics very quickly. Water tank sender floats and the whale galley sink foot pump go south very fast.

I would suggest

1. Adding chlorine only on a occasional and limited basis to make certain your tanks are kept clean. Remember that bacteria are not the only causes of gastrtoenteritis.

2. Install lexan inspection ports on your water tanks...so you can SEE if they get fouled.

3. Install a 10 filter below the galley sink and a tap filter, like a PUR, at the tap.

I have used a standard 10 inchfilter below the sink with a PUR tap water filter at the tap for over 3 yrs. Never a problem and water is perfectly clean. This combination would cost you $60 and is simple to install. The 10 inch filter I have under the sink states that it filters out giardia, as does the PUR. Not a bad idea.

If I were going places where I thought the water supply might be questionable, I think the Sea Gull filter would be a great choice. It is a true sub micron filter and is very robust. Expensive though. If you google, you may find other, very good, ceramic, sub micron water filters a bit less expensive.

One other note...you do need to change the above filters (the 10 inch under sink and PUR) on a regular basis. It is also a good idea to get a clear housing for the 10 inch under sink filter....so you can see when sediment and other junk builds up outside the filtered water.

Hope this helps.

best

John

[hellosailor]

John, I'm not sure there is a "standard" 10" water filter any more. Last year I went through three "standard" filters before getting the correct one to fit and work properly in a "standard" housing, apparently the vendors are playing proprietary again and labels are unclear about the small differences.

Somehow in the 60's and 70's campers just looked for clean water in the woods and no one really mentioned getting sick from it. But 20 years later...everyone seems to think water is going to be just plain toxic, everywhere. I'd still rather boil it to make sure--but what the hell happened over those 20-30 years?

[John Drake]

I too can remember when I was a Boy Scout, camping out, we never worried about water and I also can remember when everyone would have thought that selling water in a bottle was a joke. Times change I guess.

I have not run into a problem with standard, 10 inch filters. I got the filter I have from a hardware store...not a marine store. I believe it is a GE system. Other filters from other brands have worked fine...you just have to look to see that they are the right dimensions. There ARE many many different types of filtration systems out there, all different shapes and sizes. The inexpensive system I have seems to be a fairly established (read: old) type that seems ubiquitous.

Anything is better than nothing....should you want to do ...something.

[And....well...keep in mind that not long ago gastroenteritis was the 2rd leading cause of death world wide, second only to malaria. Of course with the modernization of the developing world, these terrible diseases have been replaced and surpassed by ischaemic heart disease, lower respiratory infections and HIV/AIDS. But, gastroenteritis is now higher up than malaria though, battling AIDS for the #3 spot in developing countries. Oh well...globalization...but this digresses, sorry. For data see: WHO | The top 10 causes of death]

[CarlF]

I used one of these filters last summer. It was probably overkill but at $15 it seemed good insurance. If you look around, you can find very cheap prices for all of this stuff. My filters holders are just lying in the bilge under the galley floorboards.

KX Matrikx Ceramikx 20-250-190-975 Only $15

The only down side is that it clogged pretty quickly. I think I'll add a 5 micron filter upstream.

I'm also thinking of plumbing the output of the filters into some sort of sealed container in the fridge and then pipe the cold water out to spigots in both the galley and the cockpit. Then I can refuse to carry bottled water

Carl

[donw_s11]

Since you are only trying to purify tap water instead of desalinating sea water perhaps you should consider an inexpensive Reverse Osmosis (RO) purification system for your drinking water. It only takes 30 PSI to run, instead of the 800-1500 PSI for desalination, and will give you drinking water equivalent to the purified water you buy in the grocery store.

Systems like this can be purchased from Sams Club, or online for less than $150 USD.

I have been running a $125 USD system in my house for the last eight years, to remove the soluable minerals (mostly calcium) from our public drinking water supply. A side benefit is that we do not get a lot of the colds and flu's that are going around the neighborhood.

You can plumb the system to return the reject water from the membrane to your water tank, since it is still potable and perfectly good for showering, cooking, washing the deck, flushing the head, etc.

It is a good idea to buy an inexpensive "Total Dissolved Solids" (TDS) meter to monitor the performance of the system. It will let you know when the filters or the membrane need changing.

regards,

Don W.+

[hellosailor]

RO for household drinking water may be overkill if your local tap water isn't somehow bad. Apparently the body needs some minerals that normally come from "contaminants" in most water and there's concern that many years of drinking RO water instead of tap water could lead to problems, i.e. osteoporosis. (sp?)

John, the bottled water craze in the US reflects on bigger problems than water. Let's face it, no one wants to provide free water or free water fountains when they can sell you something instead. Try finding a working fountain in an airport or other public place now, where it conflicts with vendor sales. You can find them--often out of commission or down a back hall, hidden in an alcove.

As a society we stigmatize the folks who are too poor to buy brand name logos, the folks who brown bag instead of eating lunch out, the folks who might dare to carry their own canteen or water bottle. And especially with the school kids, we institutionalize that cruelty so they have to show their affluence, no matter how much that might hurt, by buying status goods. Like, bottled brand name water.

Of course, whether gasoline and Pepsi, or milk or bottled water, should all sell for the same price per gallon is something else entirely.

[donw_s11]

>RO for household drinking water may be overkill if your local tap water isn't somehow bad.>

Hellosailor, U R correct... It is _absolutely_ overkill to filter highly rated public drinking water to remove the 220-250 PPM TDS which have also been chlorinated to kill bacteria. OTOH, eight years of experience indicates that we _may_ be avoiding many of the colds/flu's that are passed around the neighborhood, so perhaps there is some benefit.

Considering that the cost is very low (~$250/8 years), I'm willing pay for a little overkill, and I like the taste of the water a lot better than what comes out of the tap.

Your point about the possible dangers of osteoporosis from the continuous drinking of purified water is a valid one. We also take vitamin/mineral supplements to replace the minerals that we would normally get from our city drinking water.

OTOH, if you are cruising, and question the safety of the drinking water source, RO _is_ an inexpensive way to err on the safe side.

YMMV,

Don W.

[peterroach]

A cap of bleach for every 100 gallons should do you fine unless your digestive system is very delicate. You can use other filtration for taste or piece of mind. I pulled mine out. A little minerals in the water is just what the doctor ordered.

One note - always taste the water before you put it in your tanks. You also might want to let the hose run overboard a little if it has been sitting. No telling what critters have made their house in there.