By Alan J. Garbers
Not only is choosing the right back-packing water filter confusing, so is choosing the right accessories. If you’ve read part one on this topic, you know that I purchased a MSR Sweetwater ceramic filter. And you’ll know the problems I had with it clogging.
On my next trip to the BWCA, by adding the SiltStopper pre-filter and the paper coffee filter over the pick-up screen, the MSR Sweetwater filter worked pefectly. The only remaining issue was the loose fitting bottle adapter. (MSR appears to have added a small-mouth screw-on water bottle adapter to newer versions of the Sweetwater.)
As I was having my difficulties with the Sweetwater model, my friends were using a MiniWorks water filter, also made by MSR. As if to mock my continuous efforts to make clean water, their water filter performed flawlessly, without constant cleaning! I was so impressed; I purchased a Miniworks of my own.
On both the Sweetwater and the Miniworks the filter media is a cylinder. But from my constant cleaning of the MSR Sweetwater, I knew that the filter surface was on the inside of the one-inch diameter cylinder, while the filter surface on the MSR Miniworks is on the outside of a larger 1.75-inch cylinder. What this means is that the MSR Sweetwater has approximately 7.5 inches of surface area while the MSR MIniworks has almost 18 inches of surface area! The MSR Miniworks more than doubles the filtering area of the Sweetwater! More surface area means less clogging and better flow.
Along with increased filtering area, another feature of the Miniworks is that it can screw right on top of a large-mouth Nalgene bottle! That means no more trying to hold the water bottle upright between my feet while trying to hold the bottle adapter in place and pumping the filter handle! For those that don’t have wide mouth bottles, the MSR Miniworks has an outlet nipple to attach tubing to, so it can be used with any water vessel.
Like the MSR Sweetwater the Miniworks is also field-serviceable so the filter can be cleaned if needed.
After a great deal of experimentation and use, my personal pick is the MSR Miniworks combined with the SiltStopper pre-filter. But, there are a few other items in my personal gear.
Pumping water in camp is a chore few like to do, so I also have a Platypus Gravity Works filter. The Gravity Works has two, four-liter water bags, one to put unfiltered water in, the other to collect the clean water. There’s no pumping involved. It’s as simple as filling the “dirty” water bag with up to four liters of water and hanging it so gravity draws the water through the filter cartridge, then waiting a few minutes. In as little as 2.5 minutes the “clean” bag will be filled with up to four liters of pure filtered water! No fuss, no pumping! If the filter gets dirty and the flow rate drops, simply backflush the cleaned water back through the filter cartridge.
The only downside I’ve found is that I can’t use the Platypus Gravity Works while canoeing and I consume a great deal of water while paddling.
Another handy device is the Steripen by Hydro-Photon, Inc. At $69.99 the Steripen is a plastic UV-light emitting wand that can be placed in a filled water bottle. The Steripen kit comes with a pre-filter built into a special wide-mouth Nalgene bottle lid, which is convenient. All that is needed to fill a Nalgene bottle is hold it underwater with the prefilter lid screwed on.
The Steripen doesn’t filter anything itself, and the pre-filter only takes out larger sediment. So unlike the ceramic filters, any coloring, smell, or chemicals that are in the water won’t be removed. But the Steripen does produce enough UV light to kill any harmful bacteria, viruses, and protozoa in a liter of clear water in 90 seconds. The principle works the same as in SODIS. (If you don’t know about SODIS, read my other article.)
A drawback of the Steripen is that the manufacturer recommends the use of NiMH or Lithium batteries to work reliably. With fresh new batteries, the Steripen is supposed last an average of 200 treatments, but I never seem to get the estimated life span out of anything. With regular alkaline batteries, they estimate an average of only 20 treatments. And last time I checked, there’s no place to buy new batteries in the BWCA, nor is there a cheap and light way to recharge them. Keep in mind more gear means more weight to pack. Yes, I know that sounds odd from a man that has three water filters and a Steripen in his gear. I’m seeking therapy so maybe in a few years I can part with something…
My last addition is a new product, the LifeStraw. Unlike other filters that give you a reserve of water, the LifeStraw is a point of use filter, meaning you use it like a soda straw and suck water through it. The LifeStraw is small, only about nine inches long and an inch and a quarter in diameter, small enough to go in a pocket, pack, or even hang around my neck with the lanyard. And at $19.99 it costs a fraction of what other ceramic filters cost and it is rated to filter a thousand liters of water! Captive caps keep dirt out of the filter when not in use and a brisk blow back through it will clean any debris away.
While the LifeStraw won’t replace my other filters on trips, it is now my day-hike filter. When I come across a pretty little stream and I’m thirsty, out comes my drinking cup and my LifeStraw. Okay, in reality out comes my Camelbak bite valve full of water, but if I run out of safe, clean water, I now have a backup plan. And if I’m dying of thirst on a desert hike that didn’t go as planned, and all I can find to slack my thirst is a rocky basin of water ringed with bird droppings… well, I’ll make that call when I come to it!
There are other brand and models out there but few have the network of dealers as MSR and Platypus has. So, after everything I have been through, choosing the right backpacking water filter is no longer a confusing affair!