By: On: 08/08/2017 In: Tips and Tricks Comments: 0

How to purify water on a Duke of Ed hikeIt’s literally not possible to carry all of your water requirements for a Duke of Ed Adventurous Journey, especially for Silver and Gold hikes. That’s because one litre of water weighs one kilo, so carrying two to four days worth of water would quickly put you over the recommended weight you should be carrying (the rule of thumb is no more than 25% of your body weight. For example, a 50kg person should carry no more than 12.5kg).

Don’t worry, you can still take a bag of jelly snakes and have enough water for your hike. We’ll pass creeks and tanks with water to refill your bottles: it’ll just need to be purified.

How to Purify Water

The chance of catching Giardia or Cryptosporidium on your Duke of Ed hike is pretty slim but you do not want to risk it! Diarrhoea and camping are not friends, and the symptoms can last for months.

There are four main ways to purify water:

  1. Water purification tablets
  2. Water filtration systems
  3. Ultra-violet light
  4. Boiling water

1. Water purification tablets

These use chemicals to disinfect water to make it drinkable. There are numerous types on the market using different chemicals.

Iodine tablets taste like, well, like iodine. While they treat Giardia, they do not treat the less common Cryptosporidium. Iodine is also a problem if you have thyroid problems, are pregnant or if they’re used on a long-term basis. Be aware of these potential side effects when buying an iodine-based tablet like Potable Aqua.

It’s better to use a chlorine-based purification tablet. There are a few types available:

  • Aquatabs may be available from your local chemist and treat Giardia but not Cryptosporidium.
  • Micropur is my preferred option because it tastes less like a swimming pool and treats everything. It’s the water purification tablet of choice for leading outdoor retailers (I haven’t seen it in a chemist).

Tip: I save one litre of water to drink from a bottle while the purifying tablets are working their magic in my water bladder.



Simple to use, lightweight, easy to store and transport

Doesn’t filter any visible bugs or sediment from your water

100% effective against bacteria, protozoa (check the label for giardia and cryptosporidium protection) and viruses

Wait time of up to one hour while tablets disinfect water

No ‘work’ required ie pumping water through a filter

Can add ‘flavour’ to water

2. Water filtration systems

These force water, usually pumped, through tiny filters to eliminate microscopic critters from your water. They filter out protozoa and bacteria but viruses are small enough to get through most filters. Water borne viruses aren’t prevalent in Australia so you should be okay. However, all it takes is one infected person to go to the toilet somewhere upstream and you could be exposed.

water filters



Doesn’t change taste of the water

Doesn’t eliminate viruses

After water is filtered it’s safe to drink – no additional wait time

Can be hard work and take up to five minutes to pump one litre

Filters bugs and sediment

Can be bulky and tricky to use at first

3. Ultraviolet Light

UV light destroys over 99.9% of bacteria, viruses, and protozoa including giardia and cryptosporidium. It needs non-cloudy water to be truly effective and requires batteries to operate. Steripen uv light water purifier

It can be a bit tricky if you drink from a water bladder or similar drinking system but works great in 1L bottles.



99.9% effective protecting against bacteria, protozoa and viruses

Requires batteries and non-cloudy water*

Doesn’t add ‘flavour’ to water

Uncertain results in large drinking bladders

In Sydney, you can usually find at least a trickle of clear, running water. Sediment and cloudiness isn’t really an issue in this area.

4. Boiling Water

Purifying water by boilingStill the absolute best way to treat your water. Keep it boiling for at least one minute to destroy pretty much everything nasty in the water. Boil for up to five minutes if you’re overly cautious.

Boiling water obviously requires a heat source, usually a gas stove or fire. Not ideal in the middle of the day but fine at camp in the evening.

As well as a stove, you’ll need to carry enough fuel to boil all the water you need. This may be a small amount for a Bronze Duke of Ed hike, but the weight of the extra fuel adds up if you’re doing your Silver or Gold journeys.

Your billy or saucepan may not be big enough to boil it all in one go, so you could be boiling four or five lots of water every day.



The most effective method for killing bacteria, protozoa and viruses

Needs fire, stove, fuel and a billy or saucepan

Doesn’t add ‘flavour’ to water

Time consuming to set up stove or light small campfire

Great for hot water bottles on cold nights (see our Hiking Hack below)

May need to wait for water to cool before transferring to drinking container

What do we recommend?

Okay, I know I said boiling water is the most effective, but that’s actually not what we recommend for hiking your Duke of Ed. I regularly do Gold Adventurous Journeys and only boil water in camp at night. We use water purification tablets. It’s the lightest, easiest and most effective way.


Fill your hard plastic, stainless steel or aluminium water bottle with boiling water on a cold night. Wrap it in a jacket and place it down the bottom of your sleeping bag to keep you warm. Have a great nights sleep and drink it in the morning!

Frequently Asked Questions:

Do I really need to purify creek water on my Duke of Ed hike?

The short answer is yes. You should always purify your water and you can’t carry enough for your whole journey. Water purification doesn’t take long. The negative effects of not treating water can leave you sick for days or even months in extreme cases. If you are in the mountains with no human settlement or grazing animals upstream, the water should be drinkable. However, a pristine looking high-country stream can still have some nasty stuff lurking inside. The risks aren’t worth it. Purify your water.

What will happen if I don’t purify my water?

If you are lucky, nothing. But if you’re unlucky, the phrase “explosive, foul-smelling diarrhoea” should put the fear into you!

If there is some form of human or animal faeces upstream, you expose yourself to gastro. Same if there’s a dead animal. Diarrhoea, vomiting and cramps aren’t good friends with hiking and camping. They should not share a tent together.

How much water will I drink on a Duke of Ed hike?

Two litres of water per day for bigger Duke participants and 1.5 litres for smaller people is a good base. You should actually drink that everyday anyway. If you are hiking your Duke of Ed on a hot day, you could easily increase this by 50% again. You will probably also need water to cook with at night. We humans are 60% water; the more we sweat the more fluid we need to maintain the balance.

I’m a fit, 80kg man who sweats a little bit more than the average bloke. I drink more than three litres on a full day bush walk in winter. Add a couple of hills, a heavier pack and the heat of summertime and I will drink over six litres a day. Remember, six litres of water weighs six kilograms.

If I’m on a four day gold hike with all my gear on my back, I can’t carry 24kg of drinking water, plus another 4kg to cook with at night.

Where can I find water on my DofE adventurous journey?

So now you know how to purify water while hiking, you’ll still need to find it along the track.

A topographic map shows all the water courses on your route. Blue lines indicate gullies, creeks and rivers (may be called “streams” on your map legend) where you should be able to find water. Check recent local weather reports to determine if these watercourses may actually have water in them. Your Duke of Ed Supervisor will have recent knowledge of this and there may be some information about water availability on your Adventurous Journey itinerary that we provide.

Find a nice flowing section of the creek where there is no sediment or bugs floating on the surface. Waterfalls or cascades are great; stagnant pools less so. Upstream from a campsite or populated area is always better than downstream.

Need more Duke of Ed preparation and packing tips?

Check out all our Resources, including tips for hiking in the rain and a thorough kit list.