Introduction: How to Purify Muddy Water

Picture of How to Purify Muddy Water

One of the major problems we face during camping trips is finding clean water suitable for drinking and cooking. Even though you select a camping site near a water source, one can not be sure that the water is fit for consumption. Further, what can one do in the event of an unpredictable rain, muddying the entire water source...?

Do not worry. This Instructable will take you through the steps involved in cleaning and purifying the muddiest of muddy water and make it suitable for drinking and cooking.

Step 1: Chemicals Required

Picture of Chemicals Required

Aluminium Sulfate

Aluminium Sulfate, Shortly known as Alum, when added to raw water reacts with the bicarbonate alkalinities present in water  and forms a gelatinous precipitate. This floc attracts other fine particles and suspended material in raw water, and settles down at the bottom of the container. The water over this sediment is almost clean other than some fine particles dissolved in it.

Alum is in a crystallized form which you can powder and store in a clean glass container.

Bleaching Powder Solution

Bleaching powder or chlorinated lime is used to disinfect the water from bacteria. The chlorine present in the bleaching powder solution kills almost 90% of the bacteria present in water.

Bleaching powder also known as Calcium hypochlorite is in a powdered form. Add one or two teaspoons of the powder in a glass bottle, add water and mix well. Use a metal cap for the container as it may corrode plastic cap.

Both Alum and Bleaching powder are commonly available in most of the grocery stores.

Step 2: Water Sample

Picture of Water Sample

Look at the water collected from the source after heavy rains. It is muddy and also contains lots of floating material. Now let us see how we can convert this dirty water in to clean drinkable water.

Step 3: Treatment of Muddy Water With Alum

Picture of Treatment of Muddy Water With Alum
Coagulation and Sedimentation

  • Here, I have collected the muddy water in a bucket, poured more water to overflow and brushed away most of the floating material with hand.
  • Using a fine cloth, filtered the muddy water into another vessel. The filtered water contains no floating material and less silt.
  • Took about five liters of water in a plastic bucket and added half a teaspoon of powdered Alum (that is about 50 mg which works out to 10 mg per liter of water) and stirred well.
  • This bucket of water needs to be kept still for about 6 to 7 hours so that the sediments get coagulated and settles down at the bottom.

Step 4: Draining Clean Water

Picture of Draining Clean Water

Drain out Clean Water

After about seven hours, most of the dissolved particles have settled down at the bottom of the bucket. Drained out the clean water into another vessel very slowly without disturbing the sediment.

About half a liter of water is left out in the bucket with the sediments.

The water collected thus may still contain some fine dissolved particles, which can be removed by filtration. If you carry a small water filter during camping, you can fill this water after disinfection (next step) to get more pure water.

Step 5: Disinfection

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The clean water we got by sedimentation still contains lots of bacteria, so it needs to be disinfected before being used. Here, I have used home bleach solution, which contains Chlorine.

The prescribed normal rate is about 2 drops of bleach solution per liter of water. So, I have added about nine drops into the water in the vessel and stirred well. This water may smell little bit of chlorine. Either keeping it open to air and intermittent stirring for about 30 minutes or using a portable filter to further purify the water will remove the chlorine smell.

The chlorination process kills almost 90% percent of the bacteria present in the water. Now I got about four and half a liters of clean water which I can use for cooking and drinking during my camping trip.

Step 6: Experiment in Plastic Bottles

Picture of Experiment in Plastic Bottles

I have carried out the cleaning process in a two liter water bottle. Here I have increased the Alum content to about 15 mg per liter of water. the outcome seems to be better than with 10 mg per liter of water.

Step 7: Foot Note

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Some tips on usage of Alum and Bleach solution:

  • The prescribed dosage of Alum varies from 5 mg per liter for a relatively clear water to 85 mg for a highly turbid waters like industrial waste. However, the normal dosage for drinking water is about 17 mg per liter.
  • The dosage of bleaching solution as 2 drops per liter is suggested considering 60 to 70 percent of chlorine available in the bleaching powder. you can increase or decrease the amount by smelling the chlorinated water. More chlorine smell, add some clean water. Add a few more drops in case of no smell.
  • Keeping buckets of water mixed with Alum overnight will give you enough clean water in the morning for use.
  • Over-dosage of Alum may cause temporary dizziness, diarrhea and vomiting (but not dangerous). So, take care while adding alum.
  • Bleaching solution is corrosive. Take care not to get your skin or cloth in contact with the solution.

So, Campers, do not forget to add a little bit of Alum and Bleaching solution to your camping kit next time. It may come in handy when you are in the middle of nowhere with only mud to drink


s693796 (author)2017-10-23


antoniraj (author)s6937962017-10-23


AjayghoshT1 (author)2017-03-08

sir , your contact number please..

MugishaM (author)2015-10-30

As said in the article, bleach only gets around 90% of the nasties, something like Chlorine Dioxide would do the job, but in a survivalist situation, I guess if all you ahd was Alum and bleach from the store, it's better than drinking Balderick's coffee -muddy water.

One thing I'll suggest, if you have another plastic bottle large enough, you could cut the bottom off of it, leaving the screw cap end alone, then invert the bottle, and place the muddy water to be cleaned in that, having supported the upturned bottle from falling over -say in another vessel/pot. Then, when the Alum has done its job, you can lift out the bottle, then unscrew the cap (now on the bottom) and slowly drain off the sediment without it mixing with 'clean' water.

caarntedd (author)2015-09-20

Very, very good Instructable. Thankyou for sharing.

antoniraj (author)caarntedd2015-09-21

thank you...

4WantofaNail (author)2015-09-16

Hey, one heck of an ible good sir. Great information and presented very well. I actually just picked up some alum from my local grocer. It was surprising hard to come by, took three shops before finding it. I can't believe something this useful should be this hard to come by.

antoniraj (author)4WantofaNail2015-09-18

Thank you for your nice comments. Alum is also used in Barber shops to apply on face after a shave. Good to know you got it from your local grocer.

SandeepF1 (author)2015-09-15

Pls advise quantity of Alum and Bleaching powder required to clean and disinfect 25 feet Dia Well and 12-15 feet water height.

antoniraj (author)SandeepF12015-09-16

Instead of trying to purify the water in the well, pump the water through a pressure filter, chlorinate and then use it. If you want to treat the whole well, then take water sample and follow the guidelines in this instructable for determining the quantity required for total capacity of water in the well

biofuns (author)2015-04-16

How do I purify a water well located beside a Soakaway

antoniraj (author)biofuns2015-04-16

Instead of trying to purify the water in the well, it would be better if you pump the water through a pressure filter, chlorinate and then use it for domestic purposes. Also, I would recommend to give a water sample to authorized laboratories for testing.

venkyreddy97 (author)2015-04-03

Thanks for making clear about amount of alum to be mixed with water... Which is bothering me for long time ... Now its clear like purified water after alim :-)

jithusuji (author)2015-03-08

EricK5 (author)2015-02-28

Thank you for posting this! I was thinking that my son's class might like a class in "unmaking coffee (with caveats that only the solids would be gone. A lot of the dissolved chemicals would remain)

antoniraj (author)EricK52015-02-28

thank you EricK5... I have never tried unmaking coffee. good idea for a school project

EricK5 (author)antoniraj2015-02-28


occupiest (author)2015-01-11

Yet just one crushed Moringa seed will purify one liter of water without toxic chemicals , here's how ....

BalbirS (author)2014-12-14

please advise if we add 1/2 tsp ferric alum + 1 tsp 30% bleaching powder to a bucket of water leave overnight, filter through a triple layer of hanky cloth, will the water b fit 2 drink-reply please

antoniraj (author)BalbirS2014-12-14

the amount of alum varies with every water sample based on presence of dissolved particles. please carry out tests with different percentage of alum, say 1/4 tsp, 1/2 tsp or 3/4 tsp. the water should be clean with all those particles settled in the bottom and there should not be any taste of alum. if the water is not clean increase the amount of alum. If it tastes of alum, then reduce the quantity of alum.
Secondly, the amount of bleaching powder you have mentioned seems to be on higher side. Allow the alum-mixed water to settle down overnight and only drain out the clean water from top without disturbing the sediments. if you want you can filter this water again, add a drop or two of bleaching powder solution per litre of water and use it for drinking. here again, the smell of chlorine should be barely noticeable

BalbirS (author)2014-12-14

please advise if we add 1/2 tsp ferric alum + 1 tsp 30% bleaching powder to a bucket of water leave overnight, filter through a triple layer of hanky cloth, will the water b fit 2 drink-reply please

manojkumar66 (author)2014-06-25

I am very thankful to the author because we are facing same problem. So we got an idea to purify the sedimentation occurred in water during rainy season.

Again Thankyou

Manoj Kumar,

Megasys Biotek Pvt Ltd,

KINFRA, Koratty, Thrissur Dist,

Kerala-680309, INDIA

antoniraj (author)manojkumar662014-06-25

thank you... have a good day

sciencenut (author)2014-03-04

Can you verify the quantity of powdered Alum? I would expect half a teaspoonful to be about 5 grams ( 5000mg) or about 1 gram per liter. 50mg would be just a barely visible speck of alum. Thanks

antoniraj (author)sciencenut2014-03-04

when you treat water in large quantities, 10 mg per liter (50 mg for 5 liters of water) is more than enough.Too much of alum will change the taste of water and may cause nausea & stomach upsets. However, the dosage depends on the impurities present in water. Sample tests with varying quantities of alum is normally carried out in water treatment plants and some times it is lower than 5 mg per liter of water

mehlani (author)2014-03-04

Thank you for sharing. Always nice to learn something that can potential save your life!

antoniraj (author)mehlani2014-03-04

thank you very much...

magranger15 (author)2013-10-22

Nice instructable, but I would like to state that you cant just easily find that at walmart or some place. Me and a few friends conducted a scientific experiment to see if using salt, half a lime, and the sun will purify water, and we found it works pretty well. You may want to do that in addition. I will post my scientific paper with this if you want to read it. Once again nice tutorial :)

PS. Where could you get this stuff because I cant find it at the store.

antoniraj (author)magranger152013-10-22

Thank you. Good scientific experiment you conducted there. I have saved a copy of that for future reference.

Alum and bleaching powder are the most common material used all over the world to purify drinking water. Alum is most efficient than salt as a flocculation agent and the proper dossage does not leave any taste in the water. At my place I can find them easily. Alum is also used in almost all of the barber shops, applied on face after a shave. Try some small shops instead of walmart

Breygon (author)2013-07-13

nice instructable. I used to work in a water treatment lab so can agree with this method. just a thought on speeding up the coagulation part.. some treatment works use floculants with air agitators and skim off the scum at the surface. I haven't tried but perhaps try rigging a bike tyre co2 canister to an aquarium bubbler and see if this can shorten that step (or hook up a hand pump). also if you are carrying a water filter (water jug style) for final treatment there is now one on the market that uses membrane filtration that is VERY good (designed for potable waters but I would use it in this scenario) can filter ~800NTU 0-5um particulates from 1L in <20 min to achieve <5NTU. NOTE this does not stop viruses or anything smaller than 0.01um.

antoniraj (author)Breygon2013-07-13

Breygon, you are absolutely right. that is the way most water treatment units function. I have just simplified this instructable as a guidance for persons struck up during camping with muddy water. As you suggested, the water can be filtered after chlorination to remove very fine particles with a portable water filter.

GabbieZee (author)2013-07-07

Amazing! Thanks so much for this. Clear and easy to follow!

antoniraj (author)GabbieZee2013-07-07

thank you,,,

Tezcumpapa (author)2013-06-30

I've always wondered how that was done. ...without fire. Thank you!

antoniraj (author)Tezcumpapa2013-06-30

you are welcome...

ojsefg (author)2013-06-27

This could be a great thing to teach while traveling.

antoniraj (author)ojsefg2013-06-29

thank you...

TheMrCOOLguy2 (author)2013-06-28

Cool but can't you get poisoned by drinking to much of this?

antoniraj (author)TheMrCOOLguy22013-06-29

This is the most common method used by most of the world to purify water. If you use the specified dosage of these chemicals they are not harmful.

wazzup105 (author)2013-06-28

Interesting the addition of Alum, but 6 or 7 hours.. that's a long time when you're hiking. (although it's better to carry a few liter of water for a few hours then to discover after a few hours there's not a drop in miles. Also, preparing the water in the evening at camp will make sure you have clean drinkable water the next morning)

antoniraj (author)wazzup1052013-06-28

If the water is muddy it needs time for the sediments to settle down. Clean water from steams does not require addition of Alum and can be consumed after chlorination with few drops bleach solution. I assume people start hiking / camping with some clean water from home.

Gelfling6 (author)antoniraj2013-06-28

Most do, but on longer hikes especially in the summer when the sun is beating down on you, you tend to balance between the amount & weight versus the heat. I've gotten the purifying tablets from camping goods stores, they're good, but (A) expensive, (b) you can't drink the water for 30 minutes, until the purifying tablet has finished. (the ones with the ascorbic acid 2nd tablet take away the Iodine/chemical taste, but still leaves some.)

billbillt (author)2013-06-27

This is great..Poor areas in the world need to see this..

antoniraj (author)billbillt2013-06-27


dssouthern (author)2013-06-27

Very cool. Never know when this kind of thing will come in handy.

antoniraj (author)dssouthern2013-06-27

thank you

samalert (author)2013-06-27

Niraj this is really a common method which needs to get recognition on grass root level and thank you for helping the society this was great and enlightening.

antoniraj (author)samalert2013-06-27

thank you

Aegian2424 (author)2013-06-27

wouldn't it be safer to evaporate the water?

antoniraj (author)Aegian24242013-06-27

evaporate or boil...? you can boil it to get more pure water

About This Instructable




Bio: I like to make things more simple with easily available resources. My favorite quote: A human being should be able to change a diaper, plan ... More »
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