Monday, November 30, 2015

Water Filter Comparison

Recently, a friend asked me to do a water purifier comparison between two that I’ve used off an on over the years. Those two are
Steripen:
Purificup:
The way they operate is like night and day. The Steripen is a battery powered wand and shines UV-C light into a bottle of water. UV-C is how a lot of medical instrument sterilizers work.
The Purificup on the other hand is a silver membrane cartridge filter that kills bacteria. Way too complicated for me to understand, so here it is from the Purificup Website:
The mechanism for the antibacterial effect of silver is the following; when the positively charged silver particle collides with negatively charged bacterial cell wall, it will instantly adhere to the cell wall and effectively disrupt the growth mechanism, causing bacterial lysis. Furthermore, silver can cause bacterial protein to denature, thus effect the metabolism of the pathogens. The pathogens are no longer able to respire, multiply and metabolize, and creating a difficult environment for pathogens to survive.

Water Purifier Comparison: Pros

First in the water filter comparison is the pros, or good points of each filter.
The Steripen is small, lightweight, and faster (90 seconds for a liter). Replacement batteries are smaller than replacement cartridges. No cleaning is needed. Some models use common AA batteries that are easy to find in most countries.
The Purificup is essentially hands-free. It removes odors, taste, silt and particles. The filter fits a variety of bottles or containers.
Water Purifier Comparison - Purificup Sediment
Check out the sediment in that Purificup!

Water Purifier Comparison: Cons

Next for the water purifier comparison is the cons, or bad points of each filter.
The Steripen shows random weird error messages on a flashing LED. Usually it can only be fixed by replacing the batteries. Sometime you have to push the On Switch ten or more times before it works. If you sit on the wand it will break. If you let the wand slip out of the water at all it will shut down and you have to start over. It won’t sterilize cloudy water. Some models require a screwdriver to replace the batteries. Some models require special expensive batteries that are hard to find in foreign countries. All models work much better on Lithium batteries. Airport Security Agents in several countries have pulled my Steripen out of my bag for inspection. Several then called their supervisors for permission to let me keep it. I’ve read reports of spotty performance at altitude in the cold. I’ve experienced this myself as well.
Purificup: Cartridges must be gotten from the website and a few limited retail locations. If you try to filter out too much silt or sediment the cartridge will clog up. The filter cartridge can freeze up if the compound inside is wet.

Water Purifier Comparison: Recommendations

In this water purifier comparison I am giving you some tips on how to best use each of these two.
I can only recommend the Steripen if you will mostly be using tap water near cities. Even then you would have to rely on Alkaline or Rechargeables. Neither will give satisfactory service. You could keep NiMH charged with a Goal Zero Guide 10 kit, but you would have to have two sets to rotate. The AA Steripen is heavier, and I know from personal experience that the battery cap has very tiny fingers that will break very easy. Then you’ll have to hold the batteries in with one hand while pushing the button with the other to turn it on. Sadly, I can’t recommend the Explorer at all. It uses the CR123 batteries that you will not find anywhere outside the first world. I’ve never gotten more than 20 liters out of a set of those batteries without it locking up with the random undecipherable error codes. I never had this issue with the AA pen. If you go to the support forums, you’ll see lots of others complaining.
Steripen Explorer. Small but expensive batteries don't last long
Steripen Explorer. Small but expensive batteries don’t last long
With the Purificup, I recommend that you get two filter cartridges right away. Label them “A” and “B”. If you’re going to be out for more than three days, swap out the cartridges. They seem to work better a little “dry” every few days. If it seems slow, be sure it’s vertical. I also prefer to use a threaded bottle like a Platypus though a Pepsi bottle works as well.
Water purifier Comparison purificup on a platypus
Purificup Water Purifier with a threaded bottle
Don’t screw it all the way on. The air seal will prevent the gravity feed of the water. Another thing to do if it seems slow is to shake it. The directions mention this, but no one reads the directions, right? I usually do the steps for “before first use” from the directions. Soak and flush it a couple times. The cartridge will fit in a snack ziplock bag. If I’m going to be out for a week and the water won’t be too bad I’ll take one cartridge. For Carstensz I used two filters. Even then I stressed them to the max with the dirty river water we had to drink.
To protect from freezing I put it in a neoprene water bottle slipcover. I discarded the “clean water container” from the kit. I put the rest into a neoprene bottle sleeve. This protects it from abuse as well as cold. At night just tuck it into a corner of your sleeping bag to keep it warm.
Purificup in Neoprene Bottle Sleeve
Purificup in Neoprene Bottle Sleeve
Water Purifier Comparison: Wrapping Up
And now to wrap up the water purifier comparison with a few choice comments.
In reality this water filter comparison shouldn’t be just between these two purification systems. To be totally fair I’d have to also put in iodine, chlorine, and the pump type filters. Be that as it may, between the two in this water purifier comparison, I have grown to love the Purificup, and have taken it on all my trips since last Summer. I’ve been able to purify as much water as I need. Since I started taking two cartridges, I haven’t had any glitches having to do with the filter itself.
On Carstensz (Read the Book) I had a small issue for a couple days. I had a clogged filter after a week of thick river water. I wasn’t able to get to my bag to get the second cartridge out due largely to a broken rib. For those two days I was stuck with chlorine, and that’s why I came up with the rotation suggestion above. Learn from my experience.
If you have any suggestions or comments about this brief water purifier comparison, please leave it below.