When out camping there are many situations where you may find yourself in need of clean water. If you are backcountry camping you will likely have no clean water at your tent site. Even if you are utilizing a modern campsite with clean water, there may still be times when you are out hiking for the day when you need some way to filter water from streams. Carrying water with you is an option, but depending on how long you will be out it can add significant weight to your pack. Carrying a small filter is a great option if you know you will be near water sources. Let’s go over some of the different options for water filtration.
Pump filters are easy to use and typically lightweight and small. There is a small flexible hose on one end which connects to a pump unit. The pump has a spout. You place the hose into the dirty water and squeeze the pump to draw the water through the filter and it will be forced out the spout into your water bottle. The drawback to a pump filter is that it does require a bit of energy (squeezing the pump) to filter 1 liter per minute. If you just need to fill up a water bottle while on a trail it is a good option. However, if you need to provide water for your whole camp it may not be an economical option.
The straw filter is probably the cheapest option available for a filter. The device is a tube of approximately 2 inches. One end contains the filter and the other end has a mouthpiece. You place the filter end into your water source and then suck through the mouthpiece. The water is filtered on-demand as you drink it. The most well know straw filter is the LifeStraw. At $20 it is a great inexpensive option, though its drawbacks include requiring active suction from your mouth and the inability to fill a container. A LifeStraw can only be used to drink water on demand—not save filtered water for later.
A gravity water filtration system is a great option for when you need to filter a larger amount of water. If you are providing water for your family, a whole camp, or want to store clean water for later you may want to check out a gravity-based system. The gravity filter works by containing two different waterproof bags. You fill the first bag with dirty water and hang it above the second (clean water bag). The hose that connects the two bags contains the filter. As gravity draws the dirty water through the hose it is filtered and deposited in the clean water bag. These systems can typically filter at least several liters of water at a time, require no active energy once the bag is filled, and work very well. The drawback of the gravity system is that the cost is typically higher and they take up more space and weight than a pump-based system.
The UV purifier is a relatively new technology and provides some awesome benefits. Steripen is the most well known of the UV purifiers. It is a battery-powered wand. You fill your container with dirty water, turn the Steripen on, and drop it in the water. In 30 minutes your water is purified as well as from any of the above-mentioned filter systems. The cost of a UV purifier is competitive at $50-$100, though on the high end compared to some basic pump and straw filters. The main advantage is the weight. A UV purifier is the lightest option available to filter water. Most of them weigh only several ounces. The drawback is that it requires batteries to work.
Water Purification Tablets
There are several different options for water purification tablets. Most of them are iodine-based. The tablets are cheap, lightweight, and work very well. However, they do require a dwell time to filter properly. You must wait typically 30 minutes to 4 hours before drinking the water depending on the tablets. Many people who have used them complain of the taste of the water and it is reported that using them for several days can make your stomach feel a bit off.
A Note On Viruses
For the most part, water filters do not filter out viruses such as Cryptosporidium. There is one filter that is rated for viruses and it is the MSR Guardian pump filter. It is $350 and weighs just over a pound. Because of the weight and cost, it is not recommended unless you know viruses are present in the area you will be camping in. 95% of the water you will encounter while camping or hiking will be easily cleaned with a basic filter, but it does require some pre-research to find out if viruses are present in the area you are heading to. Katadyn does make a tablet that will filter viruses as well. They are called Micropur tablets. These can be used in conjunction with a normal filter. This will ensure the water is free of sediment and clear while using the tablets to remove viruses.