I'm not sure what you mean, Brad--a tube of carbon? Is it a solid, but porous, block of material that the water sneaks its way through? I see where several supply houses do sell activated charcoal in varying particle sizes for all sorts of applications--aquariums, water filters, kidney dialysis, etc. I'd think that the higher the total surface area, the more effective the result. But a fine powder would be tough to contain in the housing, I would think. In the case of the SiltStopper, I think a powder would find its way around the filter thing and pass right on through.

I appreciate everyone's help here.

"solid, but porous, block of material"

yup. to tell you the truth, I'm not 100% sure that's the way the FP is set up, but it's my recollection. I know the Hiker/MW/etc use the carbon core. No arguments about your varied finds, just trying to describe the system in question.

Jeff, yeah, I get a liter a minute. Fresh, sometimes it seems even a little faster. After filtering for two for close to a week the flow drops off; it's pretty easy to rig a field back-flush system if you plan on doing longer trips. (just another hydration hose w/quick connect)

I have a different approach to charcoal. I went to an aquarium supply store and bought a jar of granulated charcoal, rinsed off about an ounce of it. Them I made a tiny little bag from noseeum mesh about 2 inches long by 1 inch round, filled it with the 1 ounce of charcoal and sewed up the opening. I simply drop that bag of charcoal in my drinking bottle.

For a filter, I use a Sawyer gravity filter (the old Amigo Pro).

Brad -
You posted this shot earlier:


I looked many places on how to connect the SiltStopper, and found only one reference, on REI, that states "Attach the SiltStopper such that the Red side filters the Incoming water". Seemed a simple question until I started looking.

I have to believe that direction makes a difference. You'd think MSR would mention it on their packaging....

Do you have source that says the opposite?

Thanks.

Edit: A reply from Cascade/MSR says that the filter can be used in Either direction.

Edited by greg23 on 10/25/2010 12:23:38 MDT.

The directions do say put the red side on the source. If you are using carbon in the filter, then you have to put the clear on the source, or all the carbon will get flushed out of the prefilter.

Edited by tkknc on 10/24/2010 10:04:45 MDT.

No instructions on the freestanding SiltStopper bubble pack....

The assumption is the direction does Not make a difference?
For instance the filter doesn't have a radial gradient?

Regarding carbon -

The Katadyn charcoal filter uses about 25 grams, for about 50 gallons of filtration.

I can get about 5 grams into the Siltstopper, implying about 10 gallons of filtration. Is that even worth the effort? Or does that 5 grams in a Siltstopper go a lot farther than 10 gallons?

Obviously in clear water it will last long time, but in that case, why bother with carbon at all?

Edit: I added a screen to the output end that keeps the carbon in place.

Edited by greg23 on 10/24/2010 10:27:36 MDT.

Greg, I'm having the same dilemma as you. I picked up a SiltStopper during REI's recent sale, and I went to work on activated charcoal. First I tried some cheap aquarium charcoal, which I ground down to 1.0-1.5 mm pieces in my food processor. I put 3 Micropur tabs in my 2-liter Platy dirty bag (extra, to ensure a significant chlorine taste). I tasted the water first (much chlorine taste, of course), then I ran the water through the SiltStopper and collected a sample. Still a serious chlorine taste. Then I added my Sawyer filter below the SiltStopper, let a cup flow to wet/purge the filter, then collected another sample. Still a strong chlorine taste. I then replaced the entire system and connected a Frontier Pro, with no SiltStopper. The sample I sipped tasted chlorine free!

Later, thinking the lack of good results might have related to the quality of the charcoal, I picked up a "special" and expensive aquarium charcoal concoction called Chem-Pure Elite, which also has some type of ionized beads that purportedly adsorb certain metals (maybe good if collecting water near our CO mines...). I then ran an identical set of tests as mentioned above. Same exact results!

I've sent an e-mail to Chem-Pure to see what they think about using their products in a gravity filtration system, and will hopefully learn something this week. This morning, I also sent an inquiry to Cascade Designs. I asked them which end of the SiltStopper to connect to the dirty bag, and I also asked their opinion regarding our activated charcoal trick (and if they thought of selling little mesh bags of charcoal to add to the SiltStopper).

So I'm getting fairly frustrated about this whole concept that we've been playing around with. I'm thinking that if I'm going to use AM or tablets, then I'll stick with my Frontier Pro. If I'm not worried about viruses, I'll use my Sawyer 0.1 micron filter, forgoing chemicals. Either way, I'll keep using my Coghlan's yellow filter funnel for ease of filling my Platy streamside (it also gets the bigger floaties). Hopefully, backflushing the Sawyer will remove that red dust from the Aspen area streams. I'll consider the FP disposable. Maybe Katadyn's carbon filter is the only answer to removing the chlorine taste (assuming that it really does...has anyone tried it?). But at 3+ oz, it's not too appealing to me.

I'll post again when I hear back from Cascade Designs, and also Chem-Pure. If anyone has a better experience than mine, I'd love to hear about it.

I'm interested to see what you guys come up with on this. I originally just added the carbon as an afterthought to the siltstopper. I never really thought about it not working at all though. I figured that I would need to replace the carbon after each weekend trip. Maybe there is a better carbon solution out there

On a Frontier Pro -
Is there a way to attach typical hydration tubing to each end?

Maybe this could follow a Sawyer Filter to provide activated carbon water clarification. Although rated for only 50 gallons, Aquamira states this is about half the expected thruput, and as a post-filter perhaps it would do even better.

Edit: The answer is Yes. I found the Jason Klass video associated with Frontier Pro for sale in the BPL store. He shows it there.

Edited by greg23 on 10/24/2010 15:00:45 MDT.

Good idea, Greg. It would be nice to break open a FP and see how it's made. If there are two different components--a filter, and a carbon setup--maybe there's a way to get rid of the redundant filter element somehow, to lighten it a bit and also improve flow rate. The cotton pre-filter thing could be removed as well. Whoever has the first spent FP needs to perform an autopsy on it and report back to the group. I can't find a way to open one up, and to do so forcefully would preclude getting it back together so it would function. At any rate, I'm betting that a clogged-up filter would still have some good charcoal life remaining, providing that it was used with water sources fairly free of the inorganic stuff that carbon adsorbs. But the better way is to use a new FP. The flow rate would probably remain good for the life of the activated charcoal. But we're adding 2 oz. to our gravity filtration system by adding the FP. I guess the good thing is that we would have a redundant filter in case the Sawyer fails. This might be OK for a group outing, but for my solo trips I'd rather keep things simpler and lighter.

Geeks R Us, so let's keep thinking on this...

May I refer you to this posting for what I am about to explain.

http://www.backpackinglight.com/cgi-bin/backpackinglight/reviews/display_reviews.html?forum_thread_id=5536&skip_to_post=251982#251982

After further refinement I find this “system” to perform excellently. I updated the collection bag (green in the pic) to include a sewn in 5 micron pre filter. I purchased the material from globalfiltercorp.com (Type Fiber, Micron Rating – 5, Bag Finish – Plain, Bag Size – 1, Bag Style – PESS) but I think you can buy this on line.

I use this system exclusively when I backpack with my four grand children. The filter works flawlessly and produced water from the .02 micron filter quickly and in large amounts. On a nine day trip this year with the young one I did NOT need to back flush the filter and the filtering rate did not slow substantially.....I did not quantify flow rates so I do not know exact differences if any. (I did bring a large 60 ml syringe for back flushing if needed.) Total weight of the system [SAWYER WATER PURIFIER (.02 micron) (8.75oz WET /FLUSHING SYRINGE (1.12oz)/ BAG, (5 micron) prefilter&HOSE (4.26oz)/BAG (.35oz)] – TOTAL 14.7 oz. While the system does not fall within what you would call a “light” water treatment method, as compared to chemical or UV technology, it does provide water in large amounts that are virus free in little or no time.

Edited by KENLARSON on 10/25/2010 07:41:52 MDT.

Thank you Ken for bringing this back.

It is lamentable that so much good information is so difficult to "mine".

And commendable that you and others are still here to keep the good stuff close to the top.

I agree, Ken. Thanks for posting that.

I received a reply from Cascade/MSR stating that the Siltstopper can be used in Either direction.

Edited by greg23 on 10/25/2010 14:00:34 MDT.