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Understanding Water Filtration - MUST READ

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  • Estil_Official
    Filtration is all very well when you have plenty of fresh water to filter, but what happens when all you have is gloopy mud, soggy sand or wet gravel?

    What do you do when all there is is a bunch of scrub and some Cacti or Agave plants? Filters are useless then!

    And what if your at the coast and all that's available for twenty miles is salt water?

    That, my friends, is when you need an Estil...

    Estil is the world's first multifunctional emergency survival water purification device capable of being adapted to the situation in which you find yourself. Constructed in extremely tough silicone rubber, Estil is almost indestructible and packs down to a lightweight, pocket-sized package.

    In Solar Still mode, it works by harnessing the Sun's energy to evaporate fresh water from any wetted material, be it mud, sand, gravel or succulent plant flesh. Just form a mound of whatever wet material you have available and place the Estil over it, the process of ambient distillation shall begin generating a subsistence quantity of fresh water... sufficient to keep you alive.

    In cooler temperatures, Estil can be used as a vessel for melting ice and snow or boiling water- just hang the inverted device over a fire using the four reinforced holes provided or nestle it neatly into a suitable hollow in the ground, throw in a few hot rocks from your firepit and you'll be supping down hot broth in no time!

    But the advantages don't stop there...

    Estil is shaped to fit neatly upon the head, so a user could simply apply a wet cloth to their scalp and fit the Estil over it. This has several advantages-

    a) it protects your head from the worst of the Sun's radiation, keeping you cool and alert in hot climates,
    b) it augments the process of distillation by using some body-heat to drive the evaporation process,
    c) it leaves your hands free to tackle other important survival activities.

    It might be uncomfortable, but at least it keeps you alive!

    Estil is the world's first and only multifunctional water desalination and purification device and is coming to an outlet near you soon!

    This is not quite correct:


    Distillation is often thought to render all water safe. In effect water is heated to the point of evaporation and the steam gathered and condensed. The heating action will kill all micro organisms and many chemicals (with a lower boiling point than water) will be left behind and not come across in the distillate. It is a fuel heavy and mechanism to produce large quantities of fresh water although a variety of techniques (including the “solar still” and “connected bottles” will produce small quantities in extremis). It is worth noting that some chemicals (e.g. methanol) have a lower boiling point than water and can come across in distillation.
    The facts:

    Solar Stills are distillation units that operate purely by the process of ambient distillation. Meaning they work at normal daytime (and night-time) temperatures.

    They require NO ADDITIONAL POWER SOURCE other than sunlight and the ambient surrounding temperature to adequately purify water. It is not the heat that purifies the water but the very action of evaporation, which removes 99.9% of organisms from the water.

    Additionally, even if your still is powered, you don't need to force the process by ramping up the temperature to boiling point. Ambient distillation begins at 0.1 degrees Celsius (the triple-point of water).

    Yes, that's one tenth of one degree above freezing! They are at their most efficient at temperatures just above ambient. So you can perfectly adequately distill your water with a very low flame indeed!

    Solar Stills come in all shapes and sizes and can be made at home very cheaply. See Facebook page "Solar Still Technologies" for suggested designs.

    Estil is designed for survival emergencies where pooled water is scarce.

    Estil on Cacti
    Last edited by Estil_Official; 03-24-2023, 05:30 PM. Reason: Added the detail about low-temperature purification.

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  • Black Powder
    We have a rain water capture system of which the water, as it comes out our metal roof is purified through Berky black filters...

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  • dklimbani
    Using a RO purifier is always a good choice at home but it is impossible in wild, tips shared here are great.
    Last edited by Buggyout; 04-08-2020, 11:21 PM.

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  • Nik
    What are domestic reverse osmosis systems like these days ?

    I had to tend the two big glass water stills and the several RO units in our labs.
    The former just needed their 'kettle' elements de-scaling and a really good scrub, but the latter required a heap of consumables.

    Pre-filter, DI pack, membrane module, UV steriliser, single-use gaskets etc etc. Other than the DI pack, which just required a salt flush, none of the rest could be re-furbished on-site...

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  • chrispratt
    Purchased a Reverse osmosis water filter, price is reasonable, professionals staff is very informative and not pushy. I would highly recommend osmosis water filter.Recently I am using water filtration services by KayPlumbing Services. They have an online website ou can also visit

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  • Applejack
    Been trying to go through some things that was stored way back in a closet for a long, long time in a card board box. I had forgotten about these things. Hubby helped me get the box out so I could go through it. I had some camping stuff as well as 4 seychelle water straws and 2 of the water bottles. They are dual-chambered extreme water filter straws for removing radiation from water. I had forgotten all about these. Had to go on line to find out how good they were. Seems to be very good ones. So I guess they are keepers. I am trying to get all my water filters, iodine tabs, and such together in one place with my berkey filters. I have a 6 gal bucket to set all these in so I can keep them together and be able to grab them when needed. I have sawyer straws and life straws also that I am getting together. I feel that this is the time to make sure of our inventory and that we have everything in order. We already did it with the food so now it's time for all the non food items such as the water filters, etc. Then I will know what to do better from there.

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  • ZAGran
    Boiling will kill all bugs, but it will not remove lead and such. or certain pesticides, chemicals. oil products or radiation. In fact boiling tends to concentrate these.

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  • Applejack
    We also have several ways to purify water for drinking.. That is one thing I made sure of long ago. Something that everyone should now be taking a look at for longer term use.

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  • Morgan101
    We have the Sawyer filters and a Katadyn. We also have Life Straws, Iodine tablets, and Bleach. I always thought boiling and bleach would do the job. Am I being naïve? We have several methods of boiling even if there is no power. I like to think I am prepared, but open to suggestion if I am missing something.

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    After a 21 year career in the USMC most in desert conditions I have seen how the water filters have changed. Back in the day you used a cotton bandanna to give the water its first filtering then you put in either bleach 6 drops per gallon or use the issued water treatment pills. Let me tell you every time and I mean every time we all got the runs due to the chemicals used.

    By 1990 we were issued squad and sometimes individual water filter kits so you could fill your water canteens yourself while in the field. After Gulf War One (90-91) the commercial side started producing better filters then the military used. You have many many types of filters including ones you can make yourself. Shop around to fine the best one for your usage.

    In 2017 - My new favorite is the Sawyer brand because is has the highest rating both in amount each filter can do (100,000 gallons) and lowest .001 filtering capacity (removing .99999 %), and they cost about 25 bucks each.

    If you want to pay more there are filters that will filter out heavy metals lead, mercury, etc.

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  • ZAGran
    I have both a Sawyer and a Berkey. In an emergency situation I can use the Sawyer to filter water before running it through the Berkey for drinking, the Sawyer will also be used for household water like bathing, doing dishes and such. Also anytime I need to boil water for something the Sawyer can be used. Like boiling eggs or potatoes or pasta and so on.
    Does this make sense to anyone but me?

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  • Applejack
    Originally posted by Diesel View Post
    I did not write this, was written by a guy named Catalyst on a few diff forums etc.

    Thought it was excellent and worth a re-post.

    Choosing A Water Filter

    Why do we need a drinking water system?
    More people are using drinking water systems while camping, backpacking and traveling. Why?

    * Safety. Unfortunately, most lakes, rivers and streams are full of microorganisms that can make you sick. Drinking water systems can eliminate these contaminants and make the water safer to drink.
    * Protect Yourself. Because you never know what's in the water.
    * Freedom. Be self-sufficient with a drinking water system. As long as there is a water source, you can have safe drinking water. And, lightweight drinking water systems won't weigh you down like carrying extra water.

    What's really in the water?
    Microorganisms are the primary threat in untreated water sources. They may be in any lake, river or stream, even if the water looks clean. Microorganisms generally come from animal waste and may be spread by rain and run-off.
    Beware of these 3 types of microorganisms:

    Protozoa (2 microns and larger).
    Protozoa are the largest microorganisms. Therefore, they are the easiest to filter out of the water. However, their protective shell makes them resistant to iodine and chlorine treatment alone. One common protozoa, Giardia, causes "Beaver's Fever.

    * Giardia and Cryptosporidium

    Bacteria (.2 microns and larger).
    Bacteria range in size from 0.2 to 10 microns. Large bacteria may be removed by most microfilters, but smaller bacteria can only be eliminated by a very small micron size microfilter or a purifier. Bacteria are responsible for diseases such as Cholera and Typhoid Fever.

    * E. Coli and Salmonella

    Viruses (.004 microns and larger).
    Viruses are the smallest microorganisms and cannot be reliably removed by filtration. It was traditionally thought that viruses aren't a concern in North America, but that opinion has changed. Wilderness studies suggest that 60% of all back county illnesses are actually caused by bacteria and viruses. Viruses can cause serious health problems, such as Hepatitis, Polio and Norwalk Virus. Viruses can be eliminated from water with purification, chemical disinfection, or boiling.

    * Hepatitis A, Polio, and Norwalk Virus

    What is the best way to make water safe to drink?

    * Purifying:
    Combines chemical disinfection with filtration to eliminate all three types of microorganisms.
    * Boiling:
    Bring the water to a full boil to kill microorganisms. requires energy source and takes time
    Iodine Tablets:
    * Add 1 or 2 tablets per quart and wait 20 minutes to kill the microorganisms. Takes time and adds foul taste. limited effectiveness against Giardia and not effective against Cryptosporidium.
    * Filtering:
    Microfilters may remove protozoa and most bacteria. Doesn't remove viruses. May require frequent cleaning due to clogging.

    How do I choose a drinking water system?
    Use the Drinking Water Safety Guide to help you choose the best products for your needs. It organizes drinking water systems according to the #1 concern: safe water.
    Drinking Water Safety Guide Water System Microorganisms Eliminated Microbiological Micro Rating:
    ·Protection Level No. 1 Purifier Eliminates Viruses, Bacteria and Giardia .004
    ·Protection Level No. 2 Microfilter Eliminates Giardia and Most Bacteria 0.2 to 1.0
    ·Protection Level No. 3 Filter Eliminates Giardia 1.0 to 4.0

    Purifiers: #1
    Highest safety rating Eliminates Viruses, Bacteria and Giardia, no matter what micron size
    Microfilters: #2
    # 2 safety rating Eliminates Giardia and Most Bacteria, depending on their micron size.
    Filters: #3
    # 3 safety rating only eliminates Giardia and microorganisms larger than 1 micron.

    Okay, so how do you choose the right one?
    1. Consider How Much Protection You Want
    It's impossible to know for sure if a given water supply is free of contamination. But bacterial and protozoan contamination has been estimated to be present in 90% of the United States' surface water. And water-borne viruses may be found anywhere where humans have come into contact with the water supply.

    Filters - All of the water filters that EMS carries provide reliable protection against bacteria and protozoa (one new model also provides reliable protection against viruses!). Filters are the easiest, most economical method of making water safe to drink in situations where viral protection is not needed.

    A Note on Pore Size
    The size of the holes, or "pores", in a filter determine which microorganisms get caught and which sneak through. Most filters have a small range of hole sizes. Absolute pore size refers to the size of the largest (least effective) holes. This measurement tells you which critters will be caught and which won't.

    Unfortunately, some manufacturers advertise nominal (average) pore sizes instead of absolute sizes, which can make the whole pore size issue very complex. When comparing the effectiveness of different filters, concentrate instead on which water-borne nasties the unit claims to eliminate and which it doesn't.

    Every water filter (and purifier) that EMS sells has packaging that describes which microorganisms it can protect you from. Be sure to read this information carefully before choosing a specific model.
    Purifiers - Water purifiers offer the very best protection available from contaminated water in the backcountry. Purifiers usually provide reliable protection against bacteria, protozoa and viruses. But is this extra protection worth the extra cost? It depends on your plans.

    Choosing A Water Filter Page Four
    You are at risk for viral infection any time humans have come into contact with your water supply (NOTE: viruses can be spread by everything from urinating to brushing your teeth to spitting in a stream).

    This means situations like:

    * Crowded recreation areas where sanitation systems may become overloaded from time to time.
    * Areas where infants may be in the water.
    * Backcountry sites where backcountry visitors may not have disposed of their waste properly.
    * Developing countries with basic sanitation systems.

    Areas that are susceptible to natural disasters like floods and earthquakes (which could overwhelm sanitation systems).

    Quite simply, purifiers are the best choice for any backcountry traveler who doesn't want to take any chances with their water supplies. Remember -- you never know for sure what's been going on up stream!

    2.Consider How Much Water You'll Need
    If you only backpack a few times a year, focus your attention on smaller, less expensive filters/purifiers designed to handle a limited amount of water. You may need to replace the filter elements in these models from time to time, but you'll still come out ahead in the long run. If you plan on using your filter/purifier more often (10-20 times a year), it may be more cost effective for you to choose a more expensive unit that's designed to last longer between filter replacements.

    Also keep in mind as you compare filter/purifier models that different designs work at different speeds. If your trip plans involve difficult terrain, dry conditions and/or large groups of people, look for a model that can process a lot of water quickly. If you're planning shorter trips and/or smaller groups, you maybe happier with a lighter, smaller, less expensive model.

    3.Consider Size and Weight
    Keep in mind that you'll be carrying your filter/purifier everywhere you go. Balance your desire for high water output and ease of use with your desire to keep your backpack light.

    4.Consider Ease of Operation
    Water filters/purifiers come in a variety of styles. When performance levels are similar, the decision between them is often a matter of personal taste. To decide between models, consider how easy each one is to use. Ask yourself questions like:
    ·How easy is the filter/purifier to set up and operate?
    ·If it's a pump design, how easy is it to pump?
    ·Can it be operated easily by a single person? (try it out for yourself and see!)
    ·Is it possible to connect a water container directly to the unit? If not, how easy is it to get the treated water into your water jug?
    ·Can the filter unit be cleaned to extend its usable life? How easy is it to do?
    ·What about basic maintenance procedures? Can common problems be fixed in the field?

    NOTE: If you plan on setting up camp and staying put for a while, you may want to consider a large-volume, gravity-driven system instead of one that you have to pump. Gravity-driven systems tend to be bulkier and slower than hand-held units. But they can process a large volume of water while you're out exploring, and you don't have to lift a finger!

    5.Consider Cost
    The most expensive water filters/purifiers are often the most cost-efficient when you consider their performance and longevity. If you plan on backpacking for a number of years, consider paying a little more up front so you can save money further down the trail. When comparing costs, look at:

    * The overall price of the unit.
    * The amount of water that it can treat before the filter must be replaced.
    * The cost of replacement filter/chemical elements.

    Also keep in mind that some filter/purifier elements can be "scrubbed" from time to time to clean out pores and extend their useful life. Others cannot.

    Pre-filter - Usually located at the end of the intake hose or just before the main filter. Pre-filters strain out the largest particles and cut down on wear and tear to your main filter element. Most pre-filters can be rinsed from time to time to remove caught particles.

    Depth Filter - These are blocks of filtering material, honeycombed with small passages. Water flows through the passages and microorganisms are caught inside. Some depth filters can be cleaned to improve longevity, others cannot.

    Surface/Membrane Filter - Membrane filters are perforated surfaces that strain out particles as the water passes through. Surface/membrane filters cannot be scrubbed clean.
    This is worth bringing up again as water will be very important. We all need to be prepared for safe drinking water. I have the Berkey system and love it.. Also have several of the drinking straws with filters

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  • kaz
    thanks. i wrote the company that makes the big berkery and they pretty much said it would remove it with the black filters

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  • myakka
    Thanks ZAgran. I will look on that thread for the info.

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  • ZAGran
    Drinking Water Treatability Database

    click on "Find a contaminate" and then click on whatever you are looking to remove from your water. I've posted the microcystin toxin page in another thread : true shtf situation in toledo ohio"

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