FWIW I have the katadyn and the MSR (platypus) clean stream and have given both a good drive around the block. IMO the clean stream is superior in almost every way but one.

The fliter speed of the clean stream is at least double the base camp. Quick and efficient especially since you are able to purge the line of air. It's also much easier to fill and seems to be of a sturdier material.

That being said I will still bring the base camp on trips that involve larger parties such as 4 or more. 2 gallons of water is quite a bit and is very handy. I would also consider the base camp if I was, well, base camping.

If you are solo or 2 guys on the move the clean stream is superior by far IMO.

Here’s a few tips based on what we do. 

We usually travel the last weekend in May through first week of June, so there’s usually a good bit of pollen.  If the water doesn’t look too bad, we fill 100 yards out from camp as we approach our site for the night.  We just dip the bag in the water to fill (you can rinse the output hose with filtered water before you begin collecting to clean it off).

If the water looks highly pollinated, we fill at camp, using a regular old handkerchief draped across the top to catch sediment as the water is poured from a kitchen pot.  This seems to work well with pollen.

Hang the bag high – 7 or 8 feet.  I forget what the increase is, but there’s a decent increase in water pressure for every vertical foot of travel, to help with flow rate.

We hang a rope on the same tree, vertically, with a carabiner to clip to our 6L platypus bag, hanging just above or at ground level.

If there are air bubbles, strip the tube with your fingers to pull the bubbles out.  More effective than ‘flicking’.

**Let the bag hang for 10 minutes before opening the valve – lets the sediment settle on the bottom of the bag where it will be less likely to be pulled into the filter.

***When you get to the last 2-3 inches of water in the bag, shut off the valve – this water is full of sediment and should be discarded to prolong filter life.

Following these methods, our bag works everyday on an 8 day trip, typically for lunch stops and at camp for the night/morning water needs, and lasts the whole week with only a slight decrease in flow by the end of the week.

"I too am interested in this discussion. I tried prefiltering through some mesh and it seemed the pollin just broke up smaller and went right through."

that is my conclusion also - I don't think that any screening will filter out pollen - nylon stockings ? maybe would help if going thru several layers - I don't happen to own any, so I will leave testing up to someone else.

Obviously, the more pre-filtering you can do, the longer the filter cartridge will last, regardless of whether you are using a pump filter or a gravity filter.  That is why I use coffee filters on the intake line of my pump filters, and did wrap one around the filter cartridge - it needed two to completely cover the cartridge, and I should have been using two from the start, but didn't.

Dissolved sediment is so fine that it pases thru all of the pre-filtering methods mentioned and gets caught in the pleated filter cartridge.  As I noted in a post above, it was clearly passing thru the nylon "screen" that comes as a pre-filter with the cartridge.  You cannot look thru that white nylon (or plastic? not sure) - you can blow thru it - a small sponge is provided with the cartridge to wipe off the  white screen - I could not see that there was anything to wipe off when I did clean it.  I could see that coffee filter was trapping silt or pollen, as it was at least slightly dirty when replaced.

the amount of pollen in the water varied from lake to lake - some lakes seemed to be almost pollen free, while others had a skim of yellow on the surface, and sometimes, when the sun was right, I could see suspended pollen in the water going down for several feet.

as I mentioned in the original post, the reviews I read were varied - some people had no problems, and others, including a few for BWCA  said that thier filters clogged after only a few days use

regardless, the filter worked well enough to be included on the next tandem trip.  I don't think it is worth bringing on a solo trip for me - I don't base camp - maybe if solo and base camping it is still worth bringing, as no matter how slow the filter runs, it works all the time and will give you your filtered water if you have the time.  I don't see that the extra "hassle" with the gravity filter outweighs the minimal work of pumping a gallon and a half per day for my solo tirps.  Likewise, I could spend more effort in pre-filtering the water before it goes in the blue bag (its gotta help a little, at least) - and/or go out to the middle of the lake for water, but that extra effort seems to me to be more hassle than just pumping, and accepting that the cartridge may only be good for one trip.  Keep in mind that on this trip, we typically hit the campsite after 6:00 - several times it was more like 7, and once it was 8:30 - don't really want to fool around that much for water when you hit camp that late.

Need to prestrain during pine and spruce pollen season...just sayin

My buddy has a gravity filter.  It works fine. 

My only "complaint" is with all the tubes and bags hanging from trees, our site looks like a hospital ER. 

But I've gotten over it.

prouboy

Well, I'll take a pollen problem vs. a giardia problem.  I'm gonna try the back-flush thing though and see how that work out.  After each trip I soak the filter in bleach and then run a 1/2 bag of water through it to flush.  Since I will probably be getting a new filter for next year it's worth a shot I suppose.  Too bad they dont make the filter with removable parts and simply replace the charcoal and cloth filter as prn - like my pool filter.

Quote:


How fine of mesh? I do it all the time and never had that problem.
Maybe I've just been lucky.
I clean an area free of as much pollen/particles as I can with my hand and then quickly fill the mesh covered pot. I then remove the pit and fill my water bottles. There's always visible pollen/particles on the mesh, none in the water bottle.

solotripper wrote on Jun 16^th, 2011 at 6:39pm:


I too am interested in this discussion. I tried prefiltering through some mesh and it seemed the pollin just broke up smaller and went right through.

I'm interested in this discussion as I think a gravity type filter might be something I'd want on future trips.

I'm curious about something? I take it your all filling the bag directly from the lake, either scooping the bag full or filling with a pan.

From what I can tell, pollen/sediment is the problem after repeated uses.
Do you use anything to pre-filter the water before adding to bag?
I have a very fine mesh bug net that I use to pre-screen my water before I purify with tablets. I also use womens knee-high nylons to do the same thing. Stick the pot inside and that will pre-filter the pollen/large sediment before it gets to filter and becomes a problem. Just using the fine mesh pre-filter I can't see any suspended particles in my drinking bottles, although I'm sure there is some fine sediment etc.

I think that would go a long way in extending filter output before you had to back-flush.

"Coffee filter?  Why?  Didn't your's come with the initial screen filter?"

if you mean the white nylon filter screen under the mesh, yes, the filter cartridge came that way.  That was what had me fooled as to how much the filter was clogging - when I looked at the white screen, it was WHITE and clean looking - wasn't until later when I pulled it off to clean it, that I could see how dirty brown the filter element was - i.e. pollen or sediment was going right thru the white screen.

  I don't see that coffee filters, (which did trap sediment and pollen, as they were dirty when replaced) would do any harm and have the potential to prolong any filter cartridge - I use them on the inlet hose of my pumps all the time.

At the point in time when we started using the pump filter, the flow from the gravity filter was just    .....drop .... drop ...... drop ...... maybe one or two drops a second - still working, but so slowly that it didn't provide enough water in time for dinner when we needed it - in about the same length of operating time, it went from maybe a gal and a half output to about 3 cups by the 8th or 9th day.  Still worked, and we ran it overnight for next days water, just didnt' work fast enough.


I hadn't thought about trying to back flush it with the Guide pump - likely would have helped, but how much ?  Its like you are pumping water to save having to pump water?  still, it may be worth a try