To Filter or Purify? That is indeed the question! A conundrum many that are new to backpacking face. So how exactly do you decided which safety measure to take when there are countless options available to you? It is actually very simple if you break it down in answering these three questions: Where are you going? What sources of water will be available to you along your route, at camp? What do you see yourself realistically using?
First it’s important to know where you are going, as that automatically reduces half of your options upfront! In most cases, hiking within the Unites States it is generally safe to use Filtration only. If your adventure finds you oversees, that’s when you typically want to Purify your water. Each have pros and cons just as everything does in choosing gear so let’s break it down even further, so you understand the differences and the why’s behind the answers!
Filtration: A filter either gravity fed or mechanically pushes water through an internal filter, straining out bacteria, protozoa and debris. Typically filtration alone will NOT filter viruses, as the pores sizing within the filter are not small enough to deter it slipping through. Filtration options range from lightweight to moderate weight though they are easy to use with guarantee of a quick return on clean water.
Purification: A purifier is generally an approved method that treats both bacteria and protozoa as well as eliminating viruses. It typically includes chemicals in the form of tablets or through the use of a UV light source. Most purification methods also treat Cryptosporidium, though this is only effective after an extended waiting period. Chemical treatments however do not strain out any preexisting particulate, and typically can negatively affect the taste of the water. Tablets are your lightest weight option while UV light sources require batteries (extra weight and costs) adding more functioning pieces equaling possible failure on guarantee to work properly.
Here’s a different look at the breakdown of each system since the types of harmful pathogens you’re likely to encounter wherever you go should be your biggest concerns in choosing your method.
Bacteria – eliminated by all the above systems – filters, chemical treatments, and UV purifiers.
Viruses – eliminated through iodine, chlorine dioxide and UV purifiers. Very few filters on the market eliminate viruses and are typically much heavier and more expensive.
Cryptosporidium – eliminated by filters, chlorine dioxide tablets (4hrs wait time), drops (1hr wait time) and UV purifiers (technically speaking they only paralyze or break down the toxic DNA of organisms, halting its reproduction only short term if exposed in great length to sunlight). Iodine tablets are useless in this case.
Particulate aka floating particles of the great outdoors – technically not necessarily harmful to you, but not necessarily something most people find to be appetizing. Eliminated by filers only. Back flushing your filtration system regularly is important to keep filtration effective.
You may ask the question, well why not just BOIL it?! You can, absolutely…and we DO! Often, we both filter and BOIL. Boiling water is certainly the safest method of purification. Whether you’re out camping, or in a country with inadequate or un-sanitized drinking water, boiling water will kill all germs bacteria and parasites. Giving a general rule of thumb by rapidly boiling your water for one to three minutes you’ll have water safe enough for drinking. Though in actuality the correlation of time to temperature truly does matter if you want to get technical (30mins at 160°F/ 3mins at 185°F/ instantaneously at 212°F)…but in actuality who’s bringing a thermometer with!?! Boiling water uses a significant amount more in fuel and therefore if the amount of fuel you bring is a concern to you or you don’t have a reliable source of heat, this may not be your safest method to rely on. It is generally a good idea to use boiling as a back up method, not your main source of purification. One last mention is boiling water will NOT remove chemical toxins nor will it remove any seen sediments or particulates.
Basically, we have a Four Levels of Water Identification in accessing a need for BOIL:
Level 1. WALK AWAY! This is never safe to drink! An exception might possibly be in a dire emergency situation having knowledge there is still risk in getting sick, boiled three times a charm or not! You’ll know it when you see it – these are typically stagnant agricultural ponds with animal excretion nearby or in and sediment film on top.
Level 2. SAFE TO FILTER! And maybe also BOIL! This is not a creek or river, instead is a stagnant pool but you know it’s filled fully or partial with fresh rain water. You have no way to know what or who has contaminated the water, other than the debris and particulate on top but it’s a fresh pool. This is when we opt to boil in addition to filter if this is our only water source.
Level 3. GREAT FOR COOKING! Typically a questionable creek. This is a viable water source, due to its movement of flow, but not entirely trustworthy for reasons identified nearby. If you’re already planning on cooking a hot meal for dinner, save time filtering your water and just boil instead! You’ll be just fine, unless you really just feel more comfortable doing both.
Level 4. GO FOR IT! This is your best possible scenario! Typically a fresh water lake, rivers or creeks actively flowing at a good rate per second. Mountain springs are not exactly abundant all over, but when you do find one (bubbling upward from the ground) that is already filtered fresh spring water. In many cases this is okay to drink from without filtration…if you dare! However, if downstream from the initiating source of the spring, use caution and filter – you just never know what is cascading down from above…
Now, with the decision made – filtration vs purification – you can now focus on what type of system you prefer using within the retrospective grouping. It helps to pay attention to your habits at home, simply because you want to stay as true to what you will be most comfortable with when you’re out there. Close your eyes…visualize yourself using each system from beginning to end – is this system realistic for you, will it be a good option for YOU? In regards to Filtration, you’ve got the Life Straw – Sawyer Mini/ Squeeze – Katadyn Hiker/Hiker Pro/Gravity Camp – Platypus Gravity Works – MSR MiniWorks EX – just to name a few…
So how exactly do you choose from all these options!!? That’s where knowing what sources of water will be available to you along your route is key! Will you be crossing along several small creeks or rivers along the way or are you in higher elevations where your source of water is further below you? Knowing this can answer definitively what system will be best for you!
Reviewing now only our own personal favorite Filtration Systems, rather than continuing on with talk of Purification. First and foremost, the Sawyer Mini – our personal favorite when hiking in the Southeast or even lower elevations because we are sure to cross several accessible streams along our path! It’s a quick and easy way to grab a safe and refreshing water refill. With the Sawyer Mini weighing only 1.4oz it’s an extremely lightweight and convenient option to carry. Often we combine that in a gravity fed filtration system inserted in between a dirty and clean platy bag. This saves us significant cost in comparison to buying pre-packaged gravity systems and allows for multi-use of our gear = the accessibility of the Sawyer Mini on the trail, turning no-hands required gravity fed system in camp!
The Katadyn Base Camp gravity fed filtration system is our choice system when we have large groups with us, as it is large enough to supply a large amount of filtered water without resupply. It’s best feature is its wide mouth entry to easily and quickly access enough water to fill the 10Litter capacity it holds. This system uses a carbon filter, the same as in the Katadyn Hiker/Hiker Pro pump filter. The only downside to this is weight, especially when packed out after use.
Slightly heavier in weight but a necessity when in higher elevations when our water source is slightly more inaccessible below us, the Katadyn Hiker pump is a fool proof way to ensure safe drinking water. Being a bit bulkier as it has slightly more components involved, this carbon based filter total weight is only up to 11ounces. This requires you to do all the work in filtering your water – but perhaps that means you’ll appreciate it more!