Author Topic: Group Gravity filters?  (Read 2683 times)

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Offline madmax

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Group Gravity filters?
« on: June 07, 2014, 09:14:41 AM »
What do you like and which have you had problems with?  I'ld be willing to cobble something together as well (Even semi-permanent ones), but still want input on the store bought ones too. I saw Sixfooter's homemade group filter but have forgotten the details. 

Figure 3-4 people.

School's in session.   :)
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Offline Old Philosopher

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Re: Group Gravity filters?
« Reply #1 on: June 07, 2014, 10:02:02 AM »
Don't bother walking a mile in my shoes. That would be boring. Try spending 30 seconds in my head. That will freak you right out!!

Offline Dano

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Re: Group Gravity filters?
« Reply #2 on: June 07, 2014, 10:31:30 AM »
The one OP shows above is the one I would go to if making something permanent/semi permanent.  You can also make one yourself with their inline filter.  The big advantage to these is that you can backflush when/if needed and continue.

Another route you could look at is similar, but uses a different type of filter  http://www.cheaperthandirt.com/product/CAMP-352  I know of a few guys who use this filter with good results.  Personally, I'd add  chlorine dioxide tablets after filtering since I'm guessing you're talking about using river water?

The other thing I'd consider is some type of pre-filter/sediment/siphon/strainer system to prolong the main filter life.  Since you guys are in Florida, you could even make a sand/stone prefilter system out of one 5 gallon bucket.  (Anything is better than nothing- just to save the main filter!)

Offline Draco

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Re: Group Gravity filters?
« Reply #3 on: June 07, 2014, 10:47:31 AM »
Depends on how clean the water is and how it taste.  If it is pretty clean and good tasting then I would just chemically treat it or use the filter that OP is using.  If it is more brackish I would have a charcoal filter inline as well or use a filter than includes charcoal.   

Offline madmax

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Re: Group Gravity filters?
« Reply #4 on: June 07, 2014, 10:52:41 AM »
Thanks guys.  The semi-permanent one would stay at the camp in NC.  Maybe another at home for the disaster stash.  A simple prefilter would work since I'm collecting from a small pool that is filled from a spring/seep flowing from under a big Poplar. 

In FL,  for the canoe camps and group backpacks, a bit better prefilter (Rivers, lakes, and icky well water) would be in order with a manufactured bag system.  But you don't need to be a rocket scientist to figure out a decent set-up for the prefilter.

I just saw on tv that some highschoolers had come up with a very simple system to remove chemical toxins.  It uses cut up disposable water bottles in some kinda liquid to attract and "trap" the chemicals.  I will research more on this, but it may be a great alternative to distilling.

Draco.  Charcoal removes salt?  New one on me.  I thought osmosis or distilling were the only processes that work for saltwater.
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Offline imnukensc

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Re: Group Gravity filters?
« Reply #5 on: June 07, 2014, 12:26:29 PM »
A while back, Bearhunter mentioned a Berkey water filter.  Kinda pricey, but I guess it's like anything else and ya get what ya pay for:

http://www.berkeyfilters.com/berkey-water-filters/systems/?gclid=CO_Ftbew6L4CFehQOgodgjYAZg

FWIW, charcoal or activated carbon, will not remove salt.  They are designed primarily for removing taste, odor, and color (organic compounds), but will not remove things like bacteria, metals, etc.  Of course, they will filter out "the big chunks," but plain old sand will do that.
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Offline madmax

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Re: Group Gravity filters?
« Reply #6 on: June 07, 2014, 12:51:18 PM »
Thanks I.  Those look great.  But you're right.  A little steep.

Here's a link to the shredded plastic bottle and amino acids filter concept.

http://www.wecanchange.com/sites/wecanchange.com/files/2014winners/9_12_First_Place_2014_Winner.pdf

..and the patent

http://www.google.com/patents/WO2013028659A1?cl=en
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Offline Mannlicher

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Re: Group Gravity filters?
« Reply #7 on: June 07, 2014, 01:03:27 PM »
I use the Katadyn Ceradyn filter.   This is a 10 Ltr gravity drip filter, with three filter elements.  Like most Katadyn products, it is not cheap, but it is very effective.  The filters are supposed to be good for 13,000 gallons of water.



Offline Draco

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Re: Group Gravity filters?
« Reply #8 on: June 07, 2014, 01:26:08 PM »

Draco.  Charcoal removes salt?  New one on me.  I thought osmosis or distilling were the only processes that work for saltwater.

No brackish was probably the wrong word.  More like swampy or water with off flavors.  Some of the swamp water I have had to drink while backpacking is truly nasty if you don't pass it through active charcoal. 

Offline madmax

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Re: Group Gravity filters?
« Reply #9 on: June 07, 2014, 01:41:46 PM »

Draco.  Charcoal removes salt?  New one on me.  I thought osmosis or distilling were the only processes that work for saltwater.

No brackish was probably the wrong word.  More like swampy or water with off flavors.  Some of the swamp water I have had to drink while backpacking is truly nasty if you don't pass it through active charcoal.

lol.  Tell me about it.  blech.

Sam, that looks like a great system.  We used a Katadyn on all our GC river trips.
At least it's not a femur through the pelvis.