Trouble With Water Filters

On a recent trip (Forbidden Wilderness) we ran short of water. It is something I am always prepared to deal with, as is the issue of finding water in difficult situations and desalinating it if necessary. I included this tip in that post:

‘Tip: I have learned this about water filters. When your need is greatest they do not filter water! This is a serious problem!

My late uncle Ken Jones used always to wear a felt hat (as did his father George – and so on no doubt into the mists of time). This  was a certainly sound practice and I may have Della making me some to my own design (she is a master/mistress feltmaker).

He used always to place his hat upside down into a muddy puddle using it to filter the worst of the muck then drink from the inside of the hat. At least you get a drink.

A water filter blocks almost immediately if the water is at all muddy – so if it is really only good for filtering tap water, what good is it really?

You need to make use of some sort of garment like this as my uncle/grandfather used to do. Perhaps collecting the water then pouring it though the garment filter a number of times until it is suitable for the water filter (or just for drinking)! Mind you I have drunk black water many times and I am not dead (yet)!’

Yes, this is absolutely true, your ‘wonderful’ Sawyer Mini or Katahdin etc water filter will block up almost instantly if you are in dire need and must filter really muddy water such as that from a sambar wallow, animal soak, or roadside puddle etc and you will gain no drinkable water at all from it.

It will work well in filtering crystal clear tap or stream water should you think you need to. Many people do not, including myself. It could be useful in removing eg viruses from questionable water sources in rural Nepal or somewhere but in most mountain areas in Australia the water filter will be almost completely unnecessary and largely useless.

A (wool) felt beret or beanie on the other hand will keep you head nice and warm on a cold night and also make a rather nasty puddle into something which is fit to drink.

Here are some my wife Della previously made (a little too small for me actually. I’m sure this is obvious).

If you feel you can’t make one yourself, if you type ‘wool beret’ into an eBay of Alexpress search you will see that you can buy one (delivered) for under $5. Once again I ask, ‘How much is your life worth?’

Most of these will not be wool however (like the excellent Australian standby the Kangol cap and so will not keep you nearly as warm, particularly when it is wet.  I already own several wool caps so it is just a matter of choosing which one I take with me.

PS: A beret will weigh from as little as one ounce (say 30 grams) but probably nearer to three if you want decent insulation and filtering thickness. The one shown above weighed 45 grams.

Should you chose to sew one yourself, you can buy (eg 3mm acrylic) felt from Spotlight for $22/metre – you will need at least half a metre probably. I have added links to a few excellent DIY patterns below.

I like the reversible wool hat with the ear warmers myself. I will try to make this one out of 3mm felt from Spotlight. The pattern says is fits a 32″ head (meaning I suspect 23″!) Mine is 1″ bigger than that so I will ‘stretch’ the pattern out to 24.5″ so I’m sure it is big enough and give it a try!

Therefore (in my case) this means I print the pattern out at 110% (24.5/23 = 110%). If your head is say 22″  you would print it out at 95.5% (22/23 + 95.5%0, and so on. Then just sticky tape the pages together, cut out the material and (sort of) follow the instructions. Because I am making this in felt it only has one side so the sewing will be easier.

Della’s hats (above) are to a very much simpler pattern – something like a poncho hood pattern – so only two pieces. It would work very well to filter water from a puddle. I will play with this a bit and see if it can be made to work. I will report back.

You will also notice a link to an Instructable about using different (woven) materials (felt is better) to filter water. It includes this  photo of the results which shows fairly graphically I think how this simple method will turn something which really isn’t ‘fit to drink’ (but you should if you have to) into something which you could clearly enjoy!

NB. All these samples have been filtered already. The clear one represents some very fine silk – as I said felt will do an even better job. It is what is normally used in urban water supply filters! Clearly once you get the water to the standard of clarity represented by the sample second from the left it will go through your sawyer etc t make it even better.


If you do nothing else it might be worth your while to carry a small piece of fine silk for (pre) water filtration eg enough to fold it over a couple of times and secure it to the top of your billy with a rubber band. This arrangement should only weigh about 5 grams. (i do). You can always pour the water a number of times through the silk (eg from your billy to its fry pan lid and back) until the water is clear enough to go through your Sawyer – and you can simply rinse it out when it gets a bit clogged.


See Also:

Sawyer Water Filter

A Simple Desalinater

How to Find Water


2 thoughts on “ Trouble With Water Filters”

  1. makes sense. you can carry the plunger and backwash the filter with clean water, but then you’d already have clean water so you would no longer need the water filter! the silk is a great idea

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