How is the Steripen pre filter supposed to work?

TauPhi111

WKR
Joined
Sep 10, 2017
Messages
598
Location
Ohio
can someone please educate me on how the Steripen pre-filter is supposed to work? I tried to use it on a recent elk hunt, and it didn't seem to let any water into my Nalgene bottle. I screwed the filter onto the bottle with the filter in it and dunked the bottle in a pond. After about a minute, virtually no water had gone into the bottle. I then opened the little water bottle top and dunked it back in the pond and made sure the water bottle top did not get submerged. Still virtually no water got into the bottle. I ended up just taking the filter part out and using the top just to protect the bottle threads from contamination and to insert my Steripen. Am I using this thing wrong, or is maybe this one just defective. The mesh seems incredibly fine, but I would imagine not enough to keep water out.
 
Joined
Apr 29, 2015
Messages
2,814
Location
Littleton, CO
Aron said it's a POS so I've never used mine that came in the package I got. I believe that you're supposed to close the push top, then dip it and fill the cone with water and then once it's out of the water you open the top again. The purpose being that the water isn't going in the push top, but instead the push top is allowing air to escape as the water pushes through the filter.

I carry a no-see-um head net and use that to pre-filter my water both when using my Sawyer and my Steripen. It gets almost all of the chunks out if you layer it over the opening a couple times.
 

snakelk

WKR
Joined
Apr 3, 2013
Messages
642
Location
Oregon
I use my pre-filter by the pouring method. Open the air vent on top, and pour "dirty" water into the top, letting it pass through the pre-filter. This method works for me, and it catches particulates. Apparently there's two methods, pouring or dunking. With the dunking method Steripen says to open the air vent and completely submerge the bottle (top and all) in an upright position. I've never tried this so I can't comment on how/if it indeed works.

From the SteriPen user manual:

The Pre-Filter can be used in two ways: “Pour-through” and “Immersion.”
Pour-through:
1) Screw Pre-Filter base onto Nalgene® type 32 fl. oz. (1 litre) wide-mouth
bottle until tight.
2) Insert filter cartridge into opening in Pre-Filter base with open end of
cartridge down. Twist filter cartridge to lock in place and pull air vent
valve open.
3) Pour water through filter cartridge until bottle is filled to desired level.
4) Remove Pre-Filter base and cartridge as a unit from bottle. Remove
cartridge from filter base and wipe away particulates from base with
cloth. Rinse particulates from cartridge if necessary.
5) After cleaning, screw Pre-Filter base onto water bottle until tight.

Immersion:
Note: The “O” ring on the rim of the filter base seals against the flange
of the water bottle neck to prevent untreated water from contaminating
the threads and outer rim of the bottle.
1) Screw Pre-Filter base onto
Nalgene® type 32 fl. oz. (1 litre)
wide-mouth bottle until tight.
2) Insert filter cartridge into
opening in Pre-Filter base with
open end of cartridge down.
Twist filter cartridge until it
locks into place and pull air
vent valve open.
3) Completely immerse water
bottle with Pre-Filter end up.
(See diagram to the right)
4) Once water bottle is filled to desired level, remove from water and
wipe away droplets from filter base, making sure the upper portion
of water bottle is dry.
5) Remove Pre-Filter base and cartridge as a unit from bottle. Remove
cartridge from filter base and wipe away particulates from filter base
with cloth. Rinse particulates from cartridge if necessary
 
OP
TauPhi111

TauPhi111

WKR
Joined
Sep 10, 2017
Messages
598
Location
Ohio
I was trying to use the immersion method, but my source wasn't deep enough to completely submerge the bottle. I'll guess I'll try it again in my sink at home until I figure it out. Thanks guys.
 

oldgoat

WKR
Joined
Mar 5, 2015
Messages
2,063
Location
Arvada, CO
I had good luck with mine, but I always found a spot in the springs and Creeks where there was a little water fall to set it under, never tried just submerging it. Once I figured out to open the cap for air release it just filled right up. Also have to back flush the filter, I do it every use so the prefilter doesn't clog.
 

Owenst7

WKR
Joined
Jun 19, 2017
Messages
513
Location
Reno
The o ring that's supposed to seal the threads didn't even fit the steripen bottle that came with mine. It doesn't fit any of my nalgenes either. I had the same problem with it not filling. That cap belongs in the garbage.

I just dunk my bottle in the water and prefilter with a mosquito headnet when I need to (I just hold the net over the neck when I dunk it). I use a CapCap instead of the nalgene lid so I can drink without splashing in my face. My steripen classic fits the CapCap great so I sterilize with that and hold the bottle upside down.
 
Top