Most efficient gravity filter system – need market update

The Platypus hyperflow bottle cap won't help you much, Ike, but Greg might find them interesting. I started using them with my Platy 2-liter bags, and they work great. I just pull off the bite valve piece, then attach the plastic outlet stem to the regular Platy tubing via a 1" piece of slightly larger diameter tubing (MSR's tubing works perfectly). That's the "splicing" technique I'd alluded to earlier. They also have a twist lock which is cool in that you can shut off the flow from the dirty bag if you want.

By the way, here's a heads up on a gear deal: I have an order coming tomorrow from Sunny Sports. I picked up 2-2 liter platy bottles (never know when they'll discontinue making them, and mine are getting a bit old), a couple Clean Stream replacement hose kits (for the tubing), a Quick-Disconnect kit, and the Clean Stream replacement reservoirs. All of this was ~20% off with free shipping. Like Greg, I like to use the 2-L Platys (one dirty, one clean). But I'm thinking I might want to have a 4-L dirty bag capability occasionally (hence the Clean Stream containers). I had to walk a mile to find water in RMNP a month ago, and I don't want to have make a jaunt like that twice to get my 4 liters. Luckily, I was using my 4-L Dromlite on that trip. I'm praying that one Clean Stream 4-L will be lighter than my Dromlite, or two 2-liter dirty bags.

We need a physicist to let us know if an elbow connector impedes water flow, compared with a straight connector. I'm not so sure that it does, at least not to a significant degree. Platy's Clean Stream dirty bag does have an elbow connector at its outlet. So do their Hoser and Big Zip hydration bags.

Edit: Ike, I just had an afterthought. Couldn't you take an old platy, and remove the male end of the cap from the bottle? Maybe you can figure out a way to incorporate it into the cuben bag. That would give you "Platy capability" and allow you to use the compatable Hyperflow valves I mentioned. Or any other Platy cap, for that matter.

Im pretty sure that whatever impediment it provides is still much much greater than the purifiers flow rate. Example: I removed the purifer while the water was running and had a bunch of water come out. Way more than when the purifier was free to drip on the floor.

BTW I am still woworking on the charcoal filter and should have a final non-leaky version tommmorrow.

Ok so im getting 10 minute liters. Same as the other purifier. While its true that sawyer is faster at 20 minutes, I dont mind hiking with 2 liters of water for 30 minutes waiting for the bleach to work. Looks like im going to be using the micron prefilter, bleach, and home-made charcoal. unless i suddenly get 5 min liters from the sawyer, its just not worth the hassle. Plus it will save me 9oz. So i guess were back to where we started, with the charcoal filter. I accomplished 2 out of my 3 goals. I didn't get complete purification without waiting because i had no idea the purifier would take this long. But i did get cheap treatment without needed to buy more stuff. I can always refill the activated carbon from my bulk stash, the bleach is dirt cheap, and the 1 micron prefilter is cheap as well. I give up on the sawyer, i've got other projects i need to work on. I will update on how i sealed the homemade ac filter to keep it from leaking.

My only question is: is it ok to have the caps on the platys while the bleach is killing?

Straight from John T Smith:

"Using the platypus bags will result in a very slow flow rate. They are
just not very compatible with our filter."

Now i think its fine to uset he filters with platys, since you all report fine flow rates. But He may be right, the purifiers are just too slow. They require more pressure than we are providing with 2 liter bags. I havent tried sitting though, may give that one last try before i return this purifier.

QUESTION: IF I OPEN THE TOP OF THE "DIRTY WATER BAG" SHOULD MY WATER FLOW INCREASE IF MY SET UP DOES NOT CHANGE.

KATADYN (Sarah):
"That shouldn't increase the water flow-rate on your Camp."

CASCADE DESIGNS (Nathan Hamm):
"There is going to be a small amount of vacuum created inside the closed dirty bag as water drains out.

If you open the bag then this vacuum will be released, speeding up flow.

I’ve never actually timed the difference between a closed and opened clean bag but it is somewhat noticeable in the field.

It is less noticeable with our Platypus System as these bags are more pliable, collapsible and therefore compete less with the vacuum."

SAWYER (John T Smith):
"Using the platypus bags will result in a very slow flow rate. They are just not very compatible with our filter."

NOTE: Each reply was from a different company speaking to their filter and dirty water bag setup.

i really want to love the sawyer, its definately the best technology there is. I just cannot live with that flow rate from the purifier, although i know the filters are way better. Like Ken, I was looking for a do it all non-chemical system. I will wait around, maybe sawyer will release a version with a better flow rate in the future.

In the meantime, i will use the my 1-micron prefilter, bleach drops, and homemade activated carbon filter setup. BTW to fix the leaky activated carbon filter, I put a layer of silicone around the joined plastic section. AFter it dried i put a layer of hysol for strength around it. The Granular activated carbon works great, the flow rater through the filter is at least 1 liter/minute or faster, it really flows fast. I tested with bleach, the bleach was removed by the AC. Tested with dirty water, tasted clean. I am completely satisfied. It is lighter than the sawyer and i don't have to worry about it freezing.

Ike, thanks for sharing all this info. with us. Two questions 1) What is the final weight for your 1 micron, bleach and AC system. Any chance for a pic? 2) How long are you allowing for the bleach to do its work and what baddies are you expecting it to kill in that time frame? Oh, just thought of a third one – how much bleach? I believe I've read 4-6 drops per liter on here somewhere. Thanks again.

EDIT: wrote wait instead of weight.

pics tonight Nathan

SAWYER (John T Smith):
"Using the platypus bags will result in a very slow flow rate. They are just not very compatible with our filter."

I claim hooey to the above statement.

I used a 42" hose ending in a Camelbak shutoff valve on Zip-top platy, filled to the brim, closed with beefy pliers, and water tight when I leaned on it.

I started the timer, let it cycle and started the flow on "zero". 47 seconds later the Platy was empty.

I did the same thing, except I left the top open: 47 seconds.

The only argument that "Might" be made is that the capillary action of the closed Platy could impede flow. If it did, it wasn't much.

Common sense, physics, and empirical data all say "hooey".

Greg….Are you using a Sawyer Filter OR Purifier?

For the test today – neither. I was just interested in the two flow rates.

In tests about a week ago, a Sawyer Filter.
Edit: With a Closed Platy.

In the field, a Filter.

To add more information to this over burdened thread I present my test data of two year ago.

Ambient test environment

GREEN BAG: Sea To Summit (http://www.seatosummit.com.au/showdetail.php?Code=AUDS)
Ultra-Sil™ Dry Sack – 8 Litre 17cm(dia)x 46cm / 6.5" x 18" 1.1oz/30g
(BAG TO ROLLED IN DRY BAG CLOSED CONFIGURATION)

Sea To Summit Dirty Water bag filled to minimum of 4 liters of “clear water”

WET SAWYER .02 micron purifier (8.75 oz) after charging

Outflow Tubing of 1.27 m in length (purifier at its end)
AVERAGE FLOW RATE for 39 TRIALS: 71.4 sec/ 1 liter

It all depends as Ken said, whether your using the filter or purifier.

I say "hooey" too, Greg. I think they just want to sell us their own bags. I'm getting 2 liters from my regular 2-L Platy in about 2-3 minutes (Sawyer filter + Silt Stopper + 42" hose). That's good enough for me. If I'm worried about viruses, I'll add AM, then use the slower Frontier Pro. My 'full monty' would be the Sawyer setup plus AM and a Katadyn carbon filter and the rest of the kit ( So my final setups are FP (9.3 oz.), Sawyer (11.3 oz.), and full monty (15.3 oz.). This includes two 2-L platys, hanging cord, AM (if needed), and a large Heinie can and a Coghlan's filter to fill the dirty bag. I'm think I'm done with this project now. Thanks to you all for this dialogue–it has helped me a great deal. Looking forward to seeing a photo of your final setup, Ike.

I jsut got back from my 70 mile AT hike. The homemade filter worked great. I did tests with lots of water from many sources. All tests were done by treating with bleach for 45 minutes first. Then tasting the water, then filtering, then tasting again. Only a very faint bleach taste was present in the filtered water, faint enough that i had to search to find it when the bottle was full. When the bottle was close to empty(the filtered one) the bleach taste was stronger, but i suspect it condenses somewhat at the bottom anyway. I had a slight leak around where the 5 hour energey bottle cap screwes on, but completely solved it by wrapping one of those very thin clear garbage bags around the threads, then putting the cap back on. Flow rate was at least a liter a minute, maybe faster.

If i had the fliter to do over again i would make the following changes:

Drill holes in the caps instead of cutting them out.
Put the 1/4" quick disconnects INSIDE the cap instead of gluing them on the outside. For this to work you have to sand down the diameter of the rounded portion of the base of the nipple. But i suspect this can be easily done by hand.
You would need to order 2 of the quick disconnects from USPlastcic(about .75 cents or so each), beause one is thicker than the other. The 1/4" ID hose slips off the thinner one if pulled.
I also had a drip from where the nipple is glued onto the outside of the cap, but this can be solved by putting the nipple inside the cap instead of outside. The amount of water lost due to leakage while filtering 2 liters was probably an oz or two after addressing the thread issue.

I plan on re-doing this thing at some point to address the leaky threads and will make a how-to when i get around to it.

I plan to buy a 5 gallon bag of AC and once i remake this thing, continue to use it for years. Im perfectly happy with using it + bleach. I now have no need to buy expensive filters anymore, and mine can be replinshed cheaply with bulk items which is exactly what i wanted in a filtration system. Its also light as you only need an oz or so of bleach for a long trip, and the filter weights about 2oz. Be sure to blow on the input end when done filtering to remove about 2 oz of water weight before packing up again.

Could you post pictures of your final set up for all to see?

Please do, Ike.

I"ll be happy to when I get home.

BREAK THROUGH! EUREKA! I had been researching tops and caps for some time in hopes of finding a replacement that would allow me to avoid gluing and drilling all together. I discovered the Yorker dispensing cap. Its absolutely perfect for the job. It screws right onto both the 5 hour energy bottle and the coghlans bottle. I will be testing it tonight and will do a how-to video for this filter before the end of the week when my parts come in. I will document the construction process from start to finish for everybody. I had no idea what size yorker cap to order so i ordered nearly every size, i also ordered some 2oz bottles while i was at it. Once i am able to find out exactly which parts need to be ordered from USPLASTIC i will list the item numbers for everbody. Im guessing that the parts needed for this filter will be around $2 + shipping. Then you just have to buy the charcoal and micon biodiesel material from ebay. I wasted alot of money on pvc cement, superglue, silicone adhesives, etc. With this cap there is no need to glue anymore. just screw it on. I will post a link to the youtube video later this week.

Yorker cap:
http://www.thecarycompany.com/Images1/caps/YorkerCap.jpg

It fits very snugly onto 1/4" ID hosing. The actual constructin of this activated carbon filter, now with this cap, will probably be less than 5 minutes.

Part 2 coming tommorow morning, its uploading tonight

http://www.youtube.com/watch?v=VOhrlPjjkTw

Never buy another charcoal/activated carbon filter for backpacking ever again. Never worry about leaks because this diy job uses no glue. Properties: removes chemical tastes from your water, improves water taste, easily field serviceable, self-cleaning(germs), not likey to freeze, removes foreign chemicals/contaminants, save money and time. With the purchase of bulk materials and the necessary parts you will be able to refill this system for years to come, saving you lots of dough you would have spent buying another filter. This system is meant to be used with chemical treatments like chlorine dioxide tablets or bleach. To prevent freezing, simply blow as much water out of the filter as you can when your done using it. This will also restore filter nearly back to its original weight before being used.

This filter wil also work in an inline cambelbak type system, You can easily suck water through it.

A note about results: Results will be directly dependent on the quality of your activated carbon, density inside the unit and exposure time.

See youtube description for links:

Weight: 2.3oz
Total cost Bulk purchase: $57-$67
Total cost Sample sizes: $$32-$40

Part 1
http://www.youtube.com/watch?v=VOhrlPjjkTw

Part 2;
http://www.youtube.com/watch?v=ZSyLXavJA-o

(1.)Suitable activated carbon(I have not tried the 20×50 sizes, they may seep through 1 micron material I dunno. Check the size chart after clicking the description):
About $30-$40 bulk or $10(shipping included):

http://www.buyactivatedcharcoal.com/granular_activated_charcoal_12x30mesh_coconut_acid_washed

http://www.buyactivatedcharcoal.com/product/granular_activated_carbon_20x50mesh

http://www.buyactivatedcharcoal.com/bone_char_8x24mesh

Calgon Activated Carbon information:
http://www.calgoncarbon.com/carbon_products/water.html
(google search calgon after deciding which you want)

samples:
http://www.buyactivatedcharcoal.com/product/SAM

(2.) 1 (or ½) Micron biodiesel filter material:
Ebay, bought bulk about $25 shipped
Bought small portion: about $10
(3.) Yorker caps from Usplastic:
#66112, #66113, #66114
$5 shipped
(4.) Coghlans contain-alls:
Online $10 shipped
Store $5
(5.) 5 Hour energy bottle:
$2
Or order the coghlans contain alls and thinner bottles off usplastic and try to come up with your own combo of thinner bottles.

ACtually i may be able to ditch my filter all together if I can obtain this material:

http://www.buyactivatedcharcoal.com/activated_carbon_fiber_cloth

Right now i use a prefilter made out of 1-micron material that i just pour my water into, aligning it over the dirty bag and letting it fall right in. Works good. Well if i can use this material, I can sew 1-2 layers of it onto my current prefilter and maybe ditch my GAC filter all together. Without a doubt it would be the lightest 1 micron removing carbon filter ever. The weight penalty would be practically nothing to sew on a few layers of that stuff. Only problem is i cant find a distributor that will sell it in small amounts. This is would significantly lighten my filtering setup.

I've been looking into making something like the bottles above but was sure there was something else out there. Might want to check out "drying tubes" that are used in laboratory equipment like the one this guy is using for this experiment:

http://www.chemistryland.com/CHM107Lab/Lab1/Lab1PreparingPurifiedWater.htm

I've been playing around with using the new Camelbak Fresh Reservoir Filter as an inline charcol filter. It only weighs about 2 oz with the charcol element included. You can splice it right inline using quick connect couplings just like what is required for the sawyer filter.

With the quick connect couplings, I can remove it and leave it home without a lot of fuss when I don't want it.

So my set up goes: dirty water bladder –> ~3' hose section –> sawyer filter –> 6" hose section –> camelbak charcol filter –> 6" hose section –> clean water bladder.

The intial filter cartridge with one charcol filter element costs $20. A 2-pack refill costs $20 as well. Each element is good for around 120 L.

It comes apart easily for washing/drying or replacing the charcol filter. Appears to be watertight so far and doesn't affect flow rates.

I'm liking it.