June 24, 2017

Types of Water Purifiers and Their Applications

In The Storage, Filtration And Purification Of Water I covered water purification pretty thoroughly. Today I want to discuss the types of purification systems and their applications, as one purifier might be a better fit in certain situations.

Gravity Fed

These systems have one reservoir to hold unpurified water and often have a second reservoir to hold the purified water. These systems use gravity to pass the water through the filter at a slow and steady pace. In my opinion these systems are often best at home or at a base camp. They are often too big and bulky to be used in the field. The plus side of these units is that they are passive. The only thing you need to do is add unpurified water and take the purified water away.

Any of the pitcher type units such as PUR and other models are gravity fed. Some bigger names geared at preparedness are Berkey and MSR .


These systems force water through the filter. In most cases there is no reservoir, the dirty water can be taken directly from a source such as a river or lake. Or you can collect dirty water in a separate reservoir. You will also need to have a container ready to collect the clean water. To me, it makes sense to have a system like this in the field, along with your water bottle or canteen.

There are in house systems that attach directly to your faucet. These are pump fed. Some popular preparedness brands are Katadyn, MSR and Lifesaver.

Water Bottles with Purifiers

With these, you add water to the bottle and use a straw of sorts to suck the water through the filter. I think these are a solid second option, but the other options may be a better primary, with the exception of the Lifesaver. The Lifesaver is considered a pump, but it is the size of a water bottle and can filter water fast enough to be useful for multiple people, once the filter has expired on the lifesaver, a failsafe will not allow it to function until the filter is replaced.


Using an ultraviolet purifier will kill viruses and bacteria but will not remove any chemicals or other contaminants. To use this method you will need a container to hold the water and place the UV source directly into the water. The water in that container will then be free of bacteria and viruses. A downside to these is that they require outside power, either from batteries of electricity.

In my opinion this is a great option for backup purification.

Steripen and TrojanUV are two companies that produce this type of purification technology.


Bleach, chlorine and Iodine water purification tablets are all methods that, like the ultraviolet, will kill bacteria and viruses, but won’t remove chemicals. In some cases such as with iodine will add a foul taste.

This, in my opinion, is another good backup method.

Final thoughts

In looking into the different brands and methods, I am very impressed with the Lifesaver. They do a lot of humanitarian work. It is their goal to end water poverty. They are trying to change the way people think about providing clean water in emergencies. Right now after a typhoon or hurricane, the thought is to bring in clean drinking water. Lifesaver is saying, “just treat the dirty water that is already there.” On their website they show a video of how the bottle works. The jerry can works the same way, though it can do more water at one time. I’m seriously considering buying one of the jerry cans. In the video the creator says that one jerry can will purify 25,000 liters.

If you’re interested in the Lifesaver products in the US, use this link to Lifesaver USA.



  1. Marianne Sabia says:

    what about potassium permaganate?

    • Chris Ray says:

      I have to admit I am not very familiar with potassium permanganate, the little bit of research I have done on it tells me this might be better used at the municipality level and not for the individual level. I don’t like any chemical as the main means to purify water, but the others are more easily found.

    • Potassium Permaganate is mainly used to control sulfur water or more specifically to nullify the hydrogen sulphide in the water. It’s expensive but effective in eliminating the smell and changing the chemical structure but like Chris said, I don’t like any chemical as a means to purify water. If absolutely necessary though, common household bleach will eliminate the sulfur smell. Make sure it is only sodium hypochlorite and/or possibly with sodium hydroxide, but NO soaps or other smells. Typically bleach comes in a 5.25 up to 6% solution. 1/8 of a teaspoon to a gallon of water. mixed well and wait at least 30 minutes.
      I like some sulfur water. Growing up in Florida we had sulfur ponds we would go swimming in before camping out and on a moonlit night they would glow green. It would keep the mosquitoes off. It does make for some pretty nasty tea or coffee though.

  2. Lifesaver seems to be doing a Great work. I like the Jerry Cans and may consider one too.
    More good info, thanks!

    I have a Big Berkey (love my Berkey, and that remind me, I need replacement filters) and several Katadyns on hand.
    Another consideration I have for helping the community in case of survival situation is to build a Slow Sand Filter. There is a lot of info out there as resource (I also have books describing how to build one). You can build one easily out of a 30 or 55 gal drum with some gravel, sand, hose and plumbing parts on hand. But do you know how?. Hesparian.org site has a great page with a drawing of the slow sand filter and other info; http://en.hesperian.org/hhg/A_Community_Guide_to_Environmental_Health:Make_Water_Safe_to_Drink

    I have a StoveTec stove with their Water Pasteurizer with WAPI for boiling water but am considering a Kelly Kettle or two to have on hand too. I also have a solar pasteurizing pack with WAPI for a small amount of water. Boiling is always the safest but some filtering may be needed first. I keep bandanas and cloth (never used) diapers handy for first filtering, then expect to use another filter depending on the water source, then boil.

    • Chris Ray says:

      I like boiling as well, it will kill bacteria and viruses, but won’t take chemicals out. That’s why I have a Berkey as well. The Lifesaver it tempting to be sure.

  3. Thanks for all the great information in this article and in the comments. I currently have a Berkey Light, and some of the “water bottle” type filters, and pool chlorine powder I already use in the swimming pool. I think I’ll buy up a few more Berkey filters, just to be extra safe.

  4. I just recently bought a sawyer .02 water purifier with bucket adapter kit which includes a faucet adapter & states it ” Removes 99.997% of Viruses, 99.99999% Bacteria, and 99.9999% Protozoa/Cysts”
    I havent gone camping yet to test the process of turning running creek water into a more healthier drinking experience. But I have tested it with faucet water and the water is alot clearer and doesnt have the metal taste that you sometimes get.
    overall satisfied with my bucket adapter kit, it can ” purify 5 gallons of water in under 45 minutes, but i’ve read of cases that its alot quicker than that, ive just relied on the faucet adapter since it’s alot faster. im currently looking into buying 2L-4L dual bags to make water purification gravity fed for camping purposes &/or emergency preparedness .

    • Chris Ray says:

      That sounds like a decent setup Omar, I’m pretty sure 5 gallons in 45 minutes is faster than my Berkey, but to be honest I’ve never times it.

  5. Margaret Kiemele says:

    Any ideas on the Seychelle water jugs and filters?
    They claim to ahve special ones that will even remove radon.
    Thank you

    • Chris Ray says:

      Margaret, I haven’t heard of Seychelle, so I took a look at their site. The straws don’t look bad, but I’m willing to be if you compared the price of their pitcher and the amount of filters needed to filter the same amount as a Berkey, the Berkey would come out on top.

      As for them being the first to have a filter to filter out radon particles, I doubt their claim. Not that they can do it, but that they’re the only ones. From my understanding it is fairly easy to filter out and any filter that has a .02 filter, should filter it out.

      Here is a statement from Nuclear War Survival Skills by Cresson H. Kearny.
      “Removing fallout particles and dissolved radioactive material from water The dangers from drinking fallout contaminated water could be greatly lessened by using expedient settling and filtering methods to remove fallout particles and most of the dissolved radioactive material. Fortunately, in areas of heavy fallout, less than 2% of the radioactivity of the fallout particles contained in water would become dissolved in water .25 If all of the radioactive fallout particles could be removed by filtering or settling methods, few casualties would be likely to result from drinking and cooling with most fallout –contaminated water.”

      They show a couple pictures of expedient filters, but most purchased filtration system is going to be better than that.
      So in short, I think their claim is kind of a non-issue and a little misleading, but that’s just my $.02

  6. Chris,

    Thanks for this information. I knew of all these products with the exception of the Lifesaver. That product seemed expensive and complex and the shelf life seemed short until I read that it also filters viruses. I’ve used boiling, chlorine, and have multiple UV lights (backpack/portable). But having a virus filter is worth some dollars, thanks!

    • Chris Ray says:

      Sure thing Steve,

      I haven’t done the math, but I am guessing the filter life might be close to a Berkey. The thing I really like about the Lifesaver is it looks like a hybrid between a Berkey and a Katadyn. You can fill the reservoir and take it with you, then filter a large amount very quickly. I’m with you, having something to take out the viruses is a must.

  7. I’m a little late getting into this conservation, but …. I’ve found the Berkey to be reliable, bulky and pretty …. not so portable. I just purchased a Sawyer Point Zero Two from Highwater Filters (best price around and fast shipping). The Sawyer is exciting. First, it is eminently portable at a couple of ounces. Second, the .02 micron absolute rating goes a long way to purify questionable water. Thirdly – 1 million liters – that’s a lot of life.

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