Water Purification

patturner · Post by **patturner** » Sep 18th, '06, 08:59

Hello all ....

My wife and I are heading to Mexico this Fall in our boat and wondered if anyone had information on water purifiers. The water in Mexico as most know is not safe for non-natives to drink. I don't really want to go to the expense of a watermaker (no time either) and have plenty of tankage to store water ..... I just need to make it safe to drink. I know there are a few manufacturers out there and a couple of different ways of purifying water, like UV and activated charcoal and of course reverse osmosis. Are any of you out there in the CD world knowledgable about any of the UV or Activated charcoal systems and if they would do the job?

Thanks,
________
Dodge 600
________
The hills dicussion

Tom in Cambria · Post by **Tom in Cambria** » Sep 18th, '06, 20:01

Hi Pat,

The water in the Baja in Mexico is safe to drink. If you're going to the mainland that's another story. The problem in the Baja is finding it. In Ensenada it's readily available at the docks. In Turtle Bay there is a spigot that sticks out of the ground to the West of the end of the pier. You can't bring the boat there, of course so you have to have your own jerry jugs. Any place there is a fish processing plant there will be good, safe water because they need it to process the fish. At Magdalena Bay as you're walking up the road from the docks you'll pass under a big crane-like looking thing that looks sort of like a travel lift. On the north side at ground level there is a spigot where you can fill jugs, but of course you still have to hunch them back to your dinghy and 5 gallons of water weighs about 40 pounds which is a load in 100 degree weather with the sun beating down. Most people get one of those little folding carts to hunch the jugs back and forth to the dinghy. In Cabo it's in spigots at the marina dock. No problem in La Paz either, but if you go to the mainland side of the Sea of Cortez you'll have to be careful about the water. An activated charcoal filter simply won't do it as we're talking about microbial bacterial germs here. A reverse osmosis filter will do it, but when they make them for boats they call them "water makers". The water at your house comes under pressure from the city so you can use that pressure to force water through the R/O membrane. The water in the tanks on your boat isn't pressurized, of course, you need a powerful pump to pressurize it enough to force it through an R/O membrane. That's what a water maker is, i.e., it takes the water from your water tank or the ocean and pressurizes it high enough to force it through the reverse osmosis membrane. That filters out the germs and also any salt so you can convert salt water or non-potable water to safe drinking water. You can kill the germs in the water by adding bleach to your water tanks and in the quatities you need to purify it you can't taste it at all. Your city adds it to your water at home so it's a taste you're used to. We've discussed quantities etc. on this board before.

Hope this helps. It's been many years since I've been down there so someone may have more current info, but things don't change very quickly in Mexico usually.

patturner · Post by **patturner** » Sep 18th, '06, 20:32

Thanks Tom,

I'll keep the info you provided for the trip down. As far as water purification goes - I'm aware of essentially three ways of water purification that will work on a boat. 1) Reverse Osmosis which works but is really expensive, 2) Two stage activated charcoal filter which supposedly also works and 3) UV light. The charcoal and UV claim to eliminate 99.99% of all viruses, bacteria and cryptosporidium as well as remove any funky tastes. I just haven't actually talked with anyone who has filled up a glass of "purified" Mexican water with one of these processes and gulped it down. Someone told me to go to a big RV place since there are so many RV's that go down to Mexico and they must do something about water.

Thanks again for the info on water in Baja - I hope to have some kind of "blog" up for the trip - if so I'll post it here for anyone who would like to "travel along".
________
Toyota van history
________
GOSSIP GIRL DICUSSION

Parfait's Provider · Post by **Parfait's Provider** » Sep 18th, '06, 21:01

I think the ShurFlo people try to encourage us to not use bleach in the water. It seems to have a deleterious affect on the innards of the pumps. Might be a good idea to take a spare pump or repair kit with you if you intend to use bleach and leave it in the tanks.

Russell · Post by **Russell** » Sep 18th, '06, 23:20

Parfait's Provider wrote:I think the ShurFlo people try to encourage us to not use bleach in the water. It seems to have a deleterious affect on the innards of the pumps. Might be a good idea to take a spare pump or repair kit with you if you intend to use bleach and leave it in the tanks.

A spare pump is a good idea reguardless, pumps break, heck everything breaks when you live aboard full time. Companies who make things for boats make them for part time cruisers and never build them to work as much as liveaboards work them.

Reguardless of where you cruise or how you feel about the shoreside water there, bleach or pool tablets in your tank is a must. Algae and other fun things will certainly grow otherwise. I have a watermaker and brown "stuff" still grows in my tanks if I dont keep it in check with bleach. I have an activated carbon filter on my galley fawcett to remove the clorine. But my normal route is my watermaker has a Y valve on it, when I first run it every few days I fill a two 2g jugs with drinking water, that wont be clorinated, then switch the valve to go to the water tanks, which get clorinated. But in the off chance I need to drink water off the tap, I have the filter there to activate.

Carry a spare fresh water pump ( and every other pump you have on board, especially all you engine pumps!!) and most definately clorinate your water, reguardless of where you are. Even the purest of water will grow things you dont want to drink.

johnny of STORK · Post by **johnny of STORK** » Sep 19th, '06, 06:48

Tom's right - the water in Baja is mostly safe to drink. The marinas on the mainland almost all have water trucks that come daily, and many boaters buy, quite cheaply, water for their tanks. We just add a little bleach to the water from the San Carlos Marina taps, and haven't had any trouble in over 20 years. Makes for a somewhat nasty taste, so for drinking, we make "bug-juice", a weak powdered juice, mix. Accidents can and do happen with the local sewers, and the overflow *always* goes into the marinas, making everything suspect. I'd go with the bottled water, if you're concerned. Are you going farther down the mainland?

Johnny

M. R. Bober · Post by **M. R. Bober** » Sep 19th, '06, 07:56

Chlorine bleach is tough on stainless steel. It is best not to allow long term contact. From what I have read, flushing a system (using a pump with stainless steel component) is probably not going to harm your pump. Adding chlorine to the water tanks on a regular basis could shorten the life of a pump.

Mitchell Bober
Sunny Annapolis (where it is as basic as OH), MD

patturner · Post by **patturner** » Sep 19th, '06, 09:25

I have plastic tanks, plastic lines and a foot pump for water. No pressure water in the system. I do plan on using chlorine in the tanks and the water filter I have on board now will remove any of that taste. Worst case scenario we go with bottled or purchase water in jerry jugs, but it would be nice to not have to hump that stuff around.

We plan on going as far South as Zihuatanejo (below Acapulco) for the Winter and then slowly heading back up Norh.
________
MISTRESSKYLLINA

Joe Peladeau · Post by **Joe Peladeau** » Sep 19th, '06, 12:45

I have a three pronged approach for water purification:

On board tanks get a shot of chlorine whether it be bleach or chlorine water purification tablets. What you want is to maintain a proper chlorine residual in your tanks. Consequently you will want to test the residual once a week. There are several test kits on the market that allow you to do this.

My galley tap has a 'Pur' activated carbon filter attached. I still don't drink this tap water but use it as a phase I water filtration.

This water is put into small 1 to 2 gallon collapsible jugs. It is then treated with my Miox pen. This is a little device that is manufactured by MSR. It makes a chlorine solution via the electrolysis of salt water. I then use the solution from the pen to treat the water in the collapsible jugs. Kills every last bio nasty known to mankind. I then use this for drinking.

My experience in using this process is that I've never been sick or suffered any intestinal discomfort.

Joe Peladeau
CD 36 Nepenthe

patturner · Post by **patturner** » Sep 19th, '06, 13:32

Joe,

I just bought one of those Miox pens. It looks like such a simple little gizmo I can't believe it actually works.

Anyway, your system sounds like a good one. My only problem is I have no pressurized water on board ..... just foot pumps and the Pur systems require a minimum of about 20psi - the foot pump creates about 4psi. Pur does make a manual pump version of their filter which is not designed to mount permanently and I guess I could consider trying to use that somehow. Pur claims that their Seagul IV water purifiers eliminates 99.99% of all organisms, viruses, bacteria, etc.

Any other thoughts?
________
VAPIR OXYGEN

Russell · Post by **Russell** » Sep 19th, '06, 14:01

Never heard of those Miox pens, very interesting, I am going to have to pick one of those up.

Phil Shedd · Post by **Phil Shedd** » Sep 19th, '06, 14:54

Having work for a municipal water utility the best way to keep your water safe is with some javex (chlorx). You will be surprised how little you need to make you water safe. 2 to 3 ppm or mg/l will do if the water is fresh and clear . For 500 liters at 2 mg/lt it takes 20 grams of javex (5%) not much 500 lt is 132 us gal

( liters*ppm/1000) = grams of cl

Grams of javex = grams of cl/.05

or (us gal/1000000)* (128/.05) = oz of javex

You may have to re add javex if the tank is full has not been used in a while . After adding the correct amount you will taste a slight amount of cl. Good tank maintainance is important. I vacuum out my tanks and lines each fall and disinfect them in the spring.

As for filters you have to be careful because in warm areas when the water has not been running bacteria can grow in filters . Best not to use one. I would not have a water filter on a boat . There should be no need it the water going into the tanks was clear in the first place.

Phil

Joe Peladeau · Post by **Joe Peladeau** » Sep 19th, '06, 15:03

Any filtration element that filters down to 0.1 microns will eliminate bio nasties. Either via the use of a ceramic or any of the other types of filter media. So the Seagull IV will do the job. You'll still need water pressure... so when you mention the Seagull IV I'm assuming you're using the portable hand pump version (the First Need Purifier?) and not their in-line system. It will be a lot of hand pumping for the daily small batches of drinking water you'll be preparing.

The Miox will do the sam job without the pumping. It's just difficult to trust the technology... especially when all you see is that 1/4 teaspoon of chemical solution that the pen provides. Hard to believe that that little drop in the bucket is going to get the job done so most of us tend to look for added insurance in the form of a pre or post filter.

It's why I use a pre-filter ahead of the Miox. I'm the first to admit that I suffer from Doubting Thomas Syndrome.

Plus, the Miox does not remove those crunchy bits of particulate that somehow always manages to find its way into your water tanks.

Hope this helps.

Joe Peladeau
CD 36 Nepenthe

The Cape Dory Board