Katadyn Water Purifiers

December 28, 2011 By Leave a Comment

I have a Sweetwater Guardian, and I like it.  It’s probably easier to pump than any other filter because of the lever it uses.  I do know (from using at REI) that it pumps easier than an MSR filter with a similar lever.  However, if I were buying a filter for the first time, I would consider an MSR Miniworks or Waterworks or a Katadyn Pocket Filter or Minifilter.  The MSR filters attach directly to a water bottle (or my MSR Dromedary water bag), so there’s no output hose to get contaminated.  The Katadyn filters seem to get the most use out of their replaceable filter elements, if their claims as to filter life are accurate.  All of those filters have the requisite pore size (.2 microns, I believe) to filter out cysts, protozoa, and most bacteria. In any case, check out the monthly panel here about water filters and contaminants, or go to rei.com and find their chart that compares the abilities of various makes and models of filters, to make sure the one you buy removes the things from the water that you want it to.  And remember this is only one opinion (mine) among many.  You may place greater emphasis on other factors in choosing a water filter. A trick to extend the life of any water filter, which I probably read in this newsgroup, is to cover the “prefilter” at the end of the intake hose that goes into the water source with a coffee filter, to strain out the larger contaminants and keep them from clogging the filter element. 

 

Filed Under: water purifier Tagged With: , , , , , , , ,

Ultraviolet Water Purifiers

December 28, 2011 By Leave a Comment

After living with intestinal distress for a long time, and driving ourselves insane trying to figure out what could have been causing it, we have finally fixed on tap water as the most likely cause. (We’ve known for a long time that the water here was hard — stains on the toilet attest to that! — and it may be that, or it may be something else.)

Who’s got a water purifier? How much did you pay, and where did you buy? What about ongoing costs — I understand you need to buy a new filter for the things every so often. Am I likely to be able to use one without bringing the wrath of the landlord on myself (that is, does the installation cause problems with existing plumbing)?

My first suggestion is to contact your water company and ask if they’d be willing to test your water. It’s usually free or under $10, and it will quite likely tell you if there’s a problem with the water. If it’s a problem with the plumbing (say, contamination from the pipes, or a backflow problem somewhere between your sewer connections and your incoming fresh water lines) you can put pressure on your landlord to repair it (or install a filtration system) and save your own cash. Check city codes as well – most cities have laws about providing safe water to tenants, and this may be a way to put pressure on the landlord as well if there does prove to be a problem.

Since we rent, we “cheated” and got a Brita container-based system because our water, while perfectly safe, is foul-tasting and smells bad. We recently “upgraded” to the square 2.5 gallon model for about $30 from a local hardware store. The filters are about $6 each and last about two months each, although we got a six-pack for Christmas last year. (Whee!) My only complaint about it is that it’s too heavy for my screwy hands to lift when it’s full, so hubby gets the chore of filling it and replacing it in the fridge.

In the past I’ve also had one of those charcoal water filters that fit on the faucet end, but to be honest I hated it. It was a total pain to replace the charcoal insert, since the hard water really gunked up the screw-threads that held it together. I was also constantly whacking it while washing dishes.

I’d steer away from an under-the-sink system that requires installation unless it’s something you can easily haul out and take with you, or your landlord is willing to deduct the cost of the system and installation from your rent (doubtful!). There’s not much point in improving someone else’s property out of your own pocket. If you can do the repair-and-deduct thing, my grandparents have an Ultrapure system that works well (they have a borderline-safe well) but was rather expensive – a few hundred bucks to install and something in the area of $20/mo. upkeep costs (the replacement filters are proprietary and sold only by this particular company). They’re sold by an MLM and they’re not very “movable” as installation means ripping out some pipes under the sink and putting this big metal canister underneath.

Actually, the best is a system that uses ultraviolet light to kill organisms in combination with some type of filtration.  The system I have sends the water thru the UV light thru a Teflon coil (the coil “tumbles” the water to reach all of the bacteria, viruses, etc.), through types of carbon
filters, and then back out thru the Teflon coil and UV light. It doesn’t waste any water at all, and there isn’t a limit to how many gallons it can produce a day.  And it doesn’t cost anywhere near $800!

Water purification is my father-in-law’s business, and his life’s work.  He produces systems that are in use by the National Institutes of Health, the Peace Corps, and various American embassies.  It’s so very important to get as much information as possible before purchasing  water purification system, as there are so many different systems out there, and they’re not all equal.

BTW pure water means many thing to many people.  The most basic definition might be ultra-pure water, UPW (the kind used high pressure boilers).  With UPW there is virtually nothing in the water but good old H2O.  Since there is no ions in UPW to carry electric current it is in fact a very good electric insulator.  Typically raw water is treated by sedimentation, filtration, ioninc exchange (or reverse osmosis), degassing and finally pollishing.  You are unlikely to find a water treatment system this through for home systems.  So even if you purify your water it won’t be ultra-pure.

The next best is a water softener followed by reverse osmosis,RO.  You can get a good quality water softener from Sears.  A good RO unit can cost $800 which will give you about eight gallons per day of drinking water.  The cost usually includes installation of storage tanks and dispensing taps.  Its important to soften the water before it goes through the RO to reduce the loading on RO membranes which need to be replaced periodically (about $140 every five years).  Also, RO isn’t exactly frugal.  For every gallon of water you drink 13 gallons are wasted.

 

Filed Under: Filter Tagged With: , , , , , , ,

Water Purifier – A Must Have Home Appliance

December 28, 2011 By Leave a Comment

We have a Pur water purifier which needs a replacement filter every so often. When we recently went to our local camping store, where the purifier was bought, to buy a new filter, we were told they are no longer allowed to sell these. There are plenty of stocks we were told, but they are not allowed to sell them, or the purifiers. However they cannot or will not say why, or whether this is a permanent or temporary state of affairs. They also refused to tell us how or where to contact the makers of the product!  They say a similar ban applies to the Sweetwater brand purifier. Does anyone know anything about why the purifier & filter are banned, &/or where to contact the manufacturer, or any other relevant information? First, understand that there is a difference between a FILTER and a PURIFIER. The former filters out bacteria and protozoa but not viruses. The latter filters out bacteria and protozoa and kills the viruses chemically. (OK, the latter may also kill any remnant bacteria and protozoa as well.)

I asked Pur what was going on (by email). Summarised, the answer was as follows: There is nothing the matter with the basic (Hiker) filter, and it has NOT been withdrawn. The carbon post-filter used sometimes with the iodine (Voyager) insert was found to be TOO effective. It took all the iodine out of the water before it had killed the bugs and wogs. OK, this seems a very reasonable explanation. If correct, it would seem that someone in Australia, probably the distributor, has got the wrong message and is taking action by himself. My understanding from Pur is that the basic non-iodised filter is still for sale, and the iodine insert may also be still for sale, but the carbon post-filter has been withdrawn while they sort out the quality control on the carbon material. Frankly, I would never use a carbon post-filter with an iodine insert for this very reason. The iodine needs to act for 5-30 minutes (depending on temperature) to get the required kill efficiency. The amount left in the water is extremely small anyhow. Yes, you can SMELL it, but I defy you to taste it.

 

Filed Under: Home Appliance Tagged With: , , , , ,

Water Filtering System

December 28, 2011 By Leave a Comment

I’m off to Nepal to do some trekking soon and considering taking a water purifier with me mainly to ensure a safe supply of drinking water but also to do my bit at reducing the plastic bottle pollution epidemic. Can anyone recommend a good purifier that’s both compact and capable of producing enough clean water for two people for the duration of the Annapurna Circuit trek I’m reckoning on about a liter each a day for twenty one days. All I can say is, make sure you have some iodine tablets (and something to kill the taste) because you never know when the darn machine’s going to break.

I had a Pur Scout, which came highly recommended by the camping shop. By my third day in Africa it melted (and it was sitting in the same bag as my cheap camera, which was fine). It wasn’t unusable but it took three people to hold it together and pump at the same time. Yes, I would say that some kind of water purification equipment is quite esential.  As many other people have said, your estimate of one liter per person per day indicates that you don’t have much experience with backpacking.  If nothing else, buying 4 liters of bottled water per day per person adds up to a lot of money.  It is also a lot of weight to carry.

When I travel in India, I use Polar Pure, a system based on iodine crystals (Kahn-Vischer method) with essentially unlimited capacity.  Problems are that the bottle has to be protected against freezing, and any kind of chemical disinfection works poorly at low temperatures.  Neither is a problem in lowland India, but 18,000 feet is a whole ‘nother question. I recommend asking advice or reading the FAQ in rec.backcountry. Generally, filters avoid problems with iodine flavor, potential toxicity, and temperature, but don’t filter out viruses, your most serious enemies. Also expensive, slow, sometimes heavy, and prone to breakdown.  Iodine kills viruses very well, but is less effective against parasite cysts. Probably a combination of coarse filter and low-concentration iodine is best.

Filed Under: water purifier Tagged With: , , , , , ,

Water Purifier

December 28, 2011 By Leave a Comment

We have a Pur water purifier which needs a replacement filter every so often. When we recently went to our local camping store, where the purifier was bought, to buy a new filter, we were told they are no longer allowed to sell these. There are plenty of stocks we were told, but they are not allowed to sell them, or the purifiers. However they cannot or will not say why, or whether this is a permanent or temporary state of affairs. They also refused to tell us how or where to contact the makers of the product!  They say a similar ban applies to the Sweetwater brand purifier. Does anyone know anything about why the purifier & filter are banned, &/or where to contact the manufacturer, or any other relevant information?

I asked after Pur purifiers in REI (US store) a few months back and they said they had a product recall on the filters (IIRC). Same story re not being allowed to sell them, but if you threatened to take the store to the OFT I am sure you can convince them to tell you how to contact Pur [assuming you bought the purifier there, say]. If you have any original packaging that should their contact details. Failing that, try

Filed Under: Health Tagged With: , , , , , ,

Water Purifier Question.

December 28, 2011 By Leave a Comment

I have a Pur Scout water purifier.
Does anyone here know if it could purify
urine in an emergency situation?
I was going to contact the company
but I could get a more objective opinion here.

You could certainly put urine through your Pur Scout, but what you’d get would not be water–you’d get purified urine. The Scout is intended to remove particulate contaminants and microbes from WATER, not urine. Urine is mostly water–it is other chemical compounds in the water that make it urine. And those chemicals are not filtered out by any purifier. The only way to get water from urine would be via distillation, and that might still be pretty icky.

Purifiers like the Scout are intended for use in rivers and streams for the removal of bacteria, viruses and particles. Not for filtering pee. Purify it how?  Remove the salts in solution or ??  I don’t believe there’s such a beast as a filter that will remove dissolved material, and if there are solids in your urine, you have other medical concerns that need attention.  In the absence of an infection, your urine should be sterile (at least to your own body) and drinkable at a pinch.  You might be better off to pee in your solar still and collect the distilled urine that way.

Filed Under: Life Style Tagged With: , , , , , ,

Water Purifier Pointer

December 28, 2011 By Leave a Comment

I am posting this info for anyone in the market for a portable water purification system.  I know a guy who has designed and is marketing one that I am considering.  He doesn’t have access to the net and I have no connection with this business, so please don’t write me about it.  Here’s the general info: 

Water Doctor portable water purification system with a 12 volt self-priming pump plugs into cigarette lighter of car and will pump water from eight feet away.  Filters water eight times before U.V. sterilization that kills any and all viruses, bacteria and microorganisms.  Built in 12 volt to 120 volt D.C. to A.C. power inverter will power cellular phone, radio, computer, or other small appliances.  Comes with 2.2 gallon storage tank but will deliver 30 gallons per day.  Optional accessories include solar panels and storage batteries.  Uses no chemicals in process.

Filed Under: water purifier Tagged With: , , , , , ,

UV Light/ Water Purifier

December 28, 2011 By Leave a Comment

We just bought a house that has well water.  The sellers were all gung-ho about a system the house has where the water runs through a clear tube past a  UV light (about the lenght of a regular fluorescent light).  It is supposed to kill the bacteria.  I am a Med Tech who has been working in Micro for 15 years and  I am not impressed.  Am I missing something here? I know UV light will kill bacteria and we use these lights in our hoods to decontaminate.  However, I thought that this killing took a little time. These bacteria are going to just wash right past this light in a flash.  Are they really zapped that fast?   I was wondering what fellow Microbiologists think of this??  I don’t  think it is worth replacing the $80 bulb once a year.  The state water test certificate came back with no coliforms.

There is a market, in fact a fairly large commercial market, for these things and some studies I have seen show appreciable drops in viable counts as a result of the exposure.  However, like you, I still have major reservations.  UV does not pass through regular glass so, unless the clear tube in your system is fused quartz, it is not likely that much UV exposure of the water is occurring. Still, large companies *do* purchase these things for treatment of their water supplies.  Someone must know something that I don’t!

Similar devices are available for industrial HVAC systems where the flow rates must mean that contaminated air spends but a brief time exposed to the UV. Nevertheless, the company blurbs contain impressive data on microbial killing purportedly carried out by independent labs.  In my limited experience some bugs are more susceptible to killing by UV than others.  We used to routinely kill high concentrations of Listeria (a billion/ml) by exposing them to UV for 10-15 seconds, whereas Salmonella typhimurium used to take several minutes to kill.  Of course if your drinking water or air were that contaminated then not even gamma radiation would help much.

Filed Under: Health Tagged With: , , , , , ,

Under the counter Water Purifiers

December 28, 2011 By Leave a Comment

I would like to know other’s experiences, both good and bad, with under-the-counter water filters. Specifically, I’d like to know what brand you purchased; whether you think you got your monies’ worth; and last, how difficult was the installation? I installed an Everpur brand filter this past weekend.  Purchased it from Camping World for just under $90.  It seems to work fine so far. Installation was somewhat complicated by the fact that I could not use any of the parts included for connecting into my water line. 

My TT uses 5/8 inch semi-hard tubing and the kit included parts for smaller diameter tubing.  Luckily, my dealer, Funtime RV in leburne, TX. was only 30 miles away and he fixed me up with the necessary parts. So what should have been a one-hour project, turned into a half day project? Oh well! IMHO, you bought one of the best under counter filters made for RV use. Now, it’s only good as long as you follow the instructions that came with it. It has to have chlorinated water and the filter must be changed on a regular schedule.  That’s what the test kit is for.  Watch the flyers, because C/W will have a twin pack of filter replacements for it at a reduced cost when compared to singles. 

I get really confused when people talk about water purifiers.  In most cases, they are nothing more than water filters, which I nderstand do not necessarily purify.  Because of all the concerns, I installed an ultraviolet unit which both filters and conditions ith ultraviolet light to kill all the bad stuff (technical term!).  Bought it thru West Marine but Boat US also has the same unit.  If you are really concerned about the safety of the water you drink (as I am), check out this equipment.  Same UV as used in hospital emergency rooms.

Filed Under: water purifier Tagged With: , , , , , ,

Ultraviolet Water Purification

December 28, 2011 By Leave a Comment

I am no expert on the ultraviolet method of water purification, but have never heard about the cancer causing aspects of it. I tend to ignore a lot There are none, as it’s the UV that causes (skin) cancer. If the unit is competantly installed (a blueish glow visible anywhere is bad news) there should not be any risk. There is certainly no risk when it comes out of the taps. The way to rate UV systems is how long the water is exposed to the UV, and how intense it is. This is measured in units like s * mw/cm^2. Exposing stuff to UV for ten times as long is as good as ten times the power for a tenth of the time. Various stuff requires different amounts of UV to kill it. The hardest stuff to kill is generally spores. The UV generated by your water purification unit is what’s called short wavelength or germicidal UV and it’s very fast and effective at killing viruses, bacteria and other nasties. If the unit is sized for your water system and operating properly, it will work and the manufacturer’s literature or web site should tell you if you have the right unit for your application. To be absolutely sure, sample the incoming and output water and have it tested. Short wavelength UV can damage skin and eyes so you should not expose yourself to UV radiation from the lamp.

An automatic shut-off switch is usually part of the unit so the UV lamp will not operate if the unit is open. The purification device should also have safety glass in the inspection port so the UV is kept inside the unit. Usually, some visible blue light can be seen through the glass, but the harmful UV is filtered out. Short wavelength UV is associated with skin cancer. If you expose your skin to the UV from sunshine or certain electric light sources over time and particularly if you have had severe sunburns when you were young, your chances of skin cancer go up. But your UV water purification unit does not expose you to UV and nothing is done to the water as it goes through the unit that would make the water cause cancer. There are none, as it’s the UV that causes (skin) cancer. If the unit is competantly installed (a blueish glow visible anywhere is bad news) there should not be any risk. There is certainly no risk when it comes out of the taps. The way to rate UV systems is how long the water is exposed to the UV, and how intense it is. This is measured in units like s * mw/cm^2. Exposing stuff to UV for ten times as long is as good as ten times the power for a tenth of the time. Various stuff requires different amounts of UV to kill it. The hardest stuff to kill is generally spores.

UV is one of the best means to treat for bacteria but it depends on a number of things as to how well UV works in a given application. Things like if the water needs pretreatment and you have it and maintain the equipment to allow the light to work as it should. Also, you have to replace the bulb in the time frame for the make of light you have. That’s usually 9000 hours (annually due to the intensity falling off due to changes in the quartz the lamp is made of etc.) for all lights that do not have an intensity meter or metering circuitry; which is finally becoming popular with more and more dealers. I’ve been selling them since 1994/19955. And it depends on the class of the light you have; A or B with A being the only type I’ll sell. The A lamp produces much more intense UV-C than the class B lights. Like 40K to 16K microwatts/centimeter squared when they are new, or the newest terminalogy, microjoules/cm2. And then there’s the proper flow control to maintain the light’s rated flow. So what light and any pretreatment do you have or need based on the raw water quality you have? No, the teacher isn’t explaining things correctly or is mistaken. UV for water is in the germicidal range of the UV spectrum; exactly it’s 254.7 nanometers which is shortwave UV-C. If the light shines on you or in your eyes that’s dangerous but then the light would be in a bad way and won’t be treating your water anyway. If you have a viewport, the light emitted from it does not contain the invisible UV-C due to it being ‘filtered’ out by the material the veiwport is made of; which is usually thick plexiglass.

Filed Under: water purifier Tagged With: , , , , , ,
« Older Posts