Water Module (Part 3)

Water Module (Part 3)

Water Treatment


Boil Water

The first method to treat water which is also among the most reliable, by the way, is to boil it. There are a number of recommendations as to how long a rolling boil should be maintained–from one minute to ten minutes–but I’m of the opinion that once it’s boiling you’re ok. Of course, there are some pathogens that are resistant to even boiling water… do as you see fit.

An obvious problem with boiling water for water treatment is the amount of fuel required to do so. A nice way to reduce your fuel needs is to consider water pasteurization instead (read this article An Inexpensive Way To Pasteurize Your Water for more info) which brings the water temperature up to about 150-160 degrees Fahrenheit–enough to kill pathogens–and holds it for the required time, something like several minutes or longer. You can use a WAPI indicator like this one or perhaps a basic candy thermometer might come in handy instead:


Though not my first choice, besides boiling, probably the most basic form of water treatment for the suburbanite is to use bleach. This article on How to Purify Water with Bleach tells you how to do so. Be sure to buy plain bleach, 5.25% to 6% sodium hypochlorite. with NO additives or scents. Understand that even when left unopened bleach begins to lose its effectiveness after six months or so. As such, you’ll need to replace your bottles regularly. The good news is that a single gallon of bleach should be able to disinfect thousands of gallons of water and be useful for other purposes such as for sanitizing dishes. Keep a bottle or two on-hand, rotated regularly, and you’ll be set for most short-term scenarios. Oh, and be sure to write the date you purchased it directly on the bottle so there’s no guessing!

Pool Shock

Some people prefer to store bleach in powdered form–as calcium hypochlorite–also known as “pool shock.” If you thought a single gallon of liquid bleach could purify a lot of water, a pound of this stuff can treat a whole lot more. In fact, that’s a major reason why people like to stock it in their preps; the other major reason is because it can be effectively stored for a long time without losing its potency.

Please understand that there are some VERY serious concerns when storing and using it, so please be very careful here. And the same warnings that pertain to liquid bleach apply here, in that, you should ensure it is pure calcium hypochlorite–usually about the 70% range–that contains no additives, anti-fungals, clarifiers, etc. This forum discussion gives some good advice on the subject and this article Drinking Water Disinfection by Jim Mc. discusses the topic also. Here are two videos about using pool shock too:

Normally, I wouldn’t mess with very technical data here or for my personal use, but I do strongly encourage you to read the MSDS for Calcium Hypocholorite before purchasing and storage.


An alternative to bleach or pool shock is the SODIS (Solar Water Disinfection) method. If you use either plastic water bottles or 2-liter soda bottles–who doesn’t these days–this method may be a good stop-gap solution for you. There are some considerations to understand but a few dozen clear 2-liter soda bottles should be enough to keep up with a small family’s needs. Here’s one article about SODIS, and another article [PDF File], as well as a video detailing the process:

Remember, that if you choose to store water in 2-liter soda bottles and store them in your freezer, I suggest you do so with CLEAR bottles so that they can also be used as SODIS treatment bottles as dyed bottles won’t work properly. As for me, I would actually prefer SODIS to chemical treatment with bleach or pool shock and, in some cases, to boiling as well because I’m (1) not ingesting bleach constantly and (2) not using up my limited fuel reserves to boil water. SODIS isn’t perfect whatsoever but it certainly has it’s place and is something you should strongly consider. FYI, apparently it’s being used with much success in many third-world countries these days.


While the temporary methods above are viable options, in my opinion, there are better choices. While I’m thinking about it, this article on Zen Water Purification, Filtration, and Treatment is a really good read regarding water treatment. Though much of it pertains to backpacking options there’s still plenty to learn regarding water treatment at home too. It starts with discussing harmful organisms, moves on to filters, then chemicals, and more.

I also suggest you read these articles Water Filtration Facts and Fiction Part One and Water Filtration Facts Pay Attention to The Nines that discuss all you want to know about the numbers and science behind water filters. With that out of the way, this section will focus on shorter-term filters, the next section will be long-term filters.

Gravity Filter (short term)

I like to let nature do as much work as possible, so I figure we should start with a simple gravity filter. Know that there are plenty of longer-term filters available and, while these options might seem best for backpacking use, they can easily be used for at-home situations too. In addition, there aer some benefits to having an easily packable gravity filter, such as for bug out needs or just plain being easier to handle.

The following Katadyn Base Camp filter (show on the left below) fits the bill nicely. It should be enough to see you through for weeks and months on end without fail. The filter is field-cleanable but you can buy an additional filter, if so desired. Another option would be a Platypus Gravityworks filter (shown in the middle below) which is essentially the same idea as the Katadyn, though, I like the Katadyn for the price. Last, the AquaPail (shown on the right below) is more of what most people consider an at-home gravity filter; it’s included here because I consider it a shorter-term filtering option:

Here’s a video of the AquaPail in action:

There are a variety of other short-term water filters but most are REALLY for use while backpacking or on the go. If possible, stick with filters that let gravity do the work rather than being something YOU need to pump.


Long-term filters come from a variety of manufacturers. The following Katadyn Pocket filter is touted as among the best backpacking option and will filter tens thousands of gallons reliably. Honestly, it’s more of a travelling or bug out option but I’ve included it here because it gets a lot of praise and can certainly be used at home if you like:

In-Line Filters

Another, much less expensive option, and one more usable at home is an in-line filter such as those made by Sawyer. I like these because the filter is flushable, which means it could theoretically be used over and over again. I have one and think it will work well if you’re setup properly because it relies on the expectation of having a faucet to connect to. If you design your system so that this is permanently in-line between transferring water from your rainwater collection barrels to storage barrels then your stored water should be ready to use at all times. While there are several versions, this one should work well:

Gravity Filter (long term)

Now we’re talking about something that can be used for years on end. The only “problem” is that you WILL need to stock additional filters, so this could get fairly expensive if you’re trying to prepare yourself for years on end without replacement parts. That said, you can get many thousands of gallons of water from a single set of filters from the following recommendations. Used wisely, that could easily be several months of potable water from a single set of filters.

Highly acclaimed in the prepper community, the Big Berkey Gravity filter (shown on the left below) is considered the “king” of long-term gravity water filters. Try to stick with the black Berkey filters as they filter more types of contaminants than do the white ceramic filters, however, the white ceramic filters should do just fine for most biological pathogens. If you prefer an alternative to the Big Berkey, I hear the AquaRain filters (shown in the middle below) are very comparable but I really don’t know much about them. Last, consider Katadyn’s TRK Drip Gravidyn filter (shown on the right below) as yet another option:

Learn more about the Berkey and AquaRain filters here:

While I’m sure the manufacturer suggests you do NOT try the following, I know many people have created a “Berkey clone” by simply purchasing the filters alone and installing them into 5-gallon buckets, such as in this article here or watch a video about it:

If it were me, I would just stick with what we know works and that’s the Berkey system. In fact, if you stock a few replacement filters then you could make the Big Berkey last a very, very long time. I should mention that a few years back, Berkey had some problems with batches of their filters failing so be sure that any filters you purchase are new stock, let’s say 2012 and newer. In case you need it, this article discusses how to know if your Berkey filters are within the suspect date range. Again, don’t take this as a slam on Berkey filters at all. Things happen, they’ve got their act in order, use what works.

Bio-Sand Filters (and more)

Another potentially renewable option for water filtration is to create a bio-sand filter. This article on How to Build a Slow Sand Filter Using a 55-Gallon Barrel may come in handy. Just know that it’s not something that you can simply throw together and expect to work that day. In fact, a bio-sand filter actually takes weeks to begin working properly. Here’s a video on the subject:

Coconut Ash

One last consideration that is similar to a bio-sand filter, in that you’re filtering dirty water through a makeshift medium you’ve created, is coconut ash. Yup. Apparently, this stuff is awesome and can filter upwards of hundreds of thousands of gallons of water. Here’s an article Water filtration on a budget – the secret’s in the coconut ash discussing it. I’ve yet to purchase any but it is on my list.

Final Thoughts

Obviously, there are a variety of water considerations, from procurement to storage and treatment. Hopefully, the above suggestions and information will help you on your way to getting your family better prepared. That said, this water module came first for a reason. The cleanliness of your water cannot be taken for granted as it takes only one microscopic organism to ruin your day. In addition, you really MUST have some water stored before an emergency and you MUST have one or two methods to procure more as needed.

I also want to briefly touch upon how much water may be needed. There are a variety of answers to this question, from a few quarts per person to several gallons each day. The short answer is that you should store as much as you can. Really! But, if I had to put a number on it then shoot for five gallons per person per day. Remember that water is life. It’s used for so much more than drinking, including cooking, bathing, personal hygiene, sanitation, washing dishes, general cleaning, and so much more. As an example, for a typical family of four over the course of two weeks and assuming you store five gallons per person, that equates to merely 280 gallons of water to store. Appropriately enough, you can fit this is a single 275-gallon IBC tote or a handful of 55-gallon barrels. And, if you can store more, then you have water for other uses, additional people, or longer term water shortages.

As a final resource, here’s a thread on The Most Important Prep: Water, A Compilation Of Threads On Storage And Treatment that will give you plenty more to read!


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