What is your favorite gravity water filter system?

We use Platypus Filter
It is very compact and easy to use... it's also very easy to backflush the filter by simply lifting the clean water bag higher than the dirty water bag.

It's pricey, but you can usually find a 20% off coupon, which is what I did when ordering from Backcountry. REI should have some coupons pretty soon too.

+1 on Platypus. Very nice

Sawyer. I sprung for the full 4L system when I first heard the rave reviews on this site, but it turns out to be pretty easy to make one with a smaller investment. Do a search here for lots of ideas.

Platypus.

Another +1 on platypus.

There is a katadyn one with a blue bag. I’ve seen two different ones get backed up on weeklong trips to Bwca. I’m sure they could have been back flushed but my Platypus didn’t have any issue.

A Platypus gravity filter system may be the best new gear we've tried in years. We have the 4 liter system and bring an extra filter with but have never needed to use it. We actually backflush every bag filtered by lifting the clean bag above the dirty bag and letting 5-6 ounces of water flow back into the dirty bag. Keeps it flowing smooth.

We pair it with 2 6 liter MSR bags and usually set up a nice water station which is convenient and allows us 16 liters of fresh filtered water available at all times. No reason not to use or drink water liberally, its just so easy.

As mentioned, there are several good systems, but my vote definitely goes to Platypus system. If you need a replacement filter for the Platypus, use the 20.00 Sawyer filter, It filters better (one micron instead of two) and is rated for many more gallons, although who knows if any ratings are accurate. They will both last a long time with back flushing.

I think the Platypus replacement is around 50.00 and may be a bit faster but still happy with Sawyer as replacement. It is easy to build a system, but I love the bags used in the Platypus, and they have changed the fittings a couple of times making it tricky to get the proper parts by just ordering the bags and using your own filter and hoses. IMHO just get the entire Platypus system.

The 5 L Lifestraw has worked well for us.

Sawyer (bottle, mini, squeeze), Platypus, MSR; anything that is backflushable in the field. Any of them are going to outlast me. There's a ton of stuff on the internet about making various gravity systems using one of those filters and various components. Some of those people are hung up on whether it takes 55 seconds or 65 seconds, but I don't stand around in camp timing it. I hang it up and do other stuff. A search here will bring up a wealth of info on making and using them.

A 2 gal bag with a big older sawyer.....homemade base camper.

We use a Sawyer with some MSR bags and some extra fittings and hose from the hardware store. Works great and makes life so much easier than pumping.

Sawyer all the way! Bottle, squeeze and gravity! Interchangeable parts use it day and in camp!

I loved my MSR Waterworks for nearly 2 decades. Tried the Sawyer Squeeze for a year and the Sawyer Mini for a few trips. Once I tried the Platypus 4 liter GravityWorks everything else was spoiled. The Platypus GravityWorks filters a lot of water fast. Back flushing is simple and easy. It is not noticably heavier than any of the other filters I've carried.

I bought mine at 30% off at REI Spring Sale.

I use a Platypus 4L with a Sawyer Mini. I like how the platy opens up wider than the Sawyer bags. We did have some problems with the mini but I think we were letting air bubbles get into the filter so now we just leave a little in the dirty bag to keep it bubble free.

"There is a katadyn one with a blue bag. I’ve seen two different ones get backed up on weeklong trips to Bwca. I’m sure they could have been back flushed but my Platypus didn’t have any issue."

My katadyn base camp filter clogged after 6 days in the BWCA. If we were going to stay any longer, we would have been boiling water. I always paddled out into the middle of the lakes to get the cleanest water I could before filtering. I can't find any way to back flush it.

Platypus hands down, lighter and simpler than the competitors, bags are easier to fill, it just works great.


But they are all beer league compared to this bad boy, wouldn’t bring on a canoe trip unless it was a very large group but it sure is nice. CNC aluminum construction, solid brass CPC quick connects, stainless spigot, heavy duty 100mil buckets, bracket has been tested to 600lbs, leaves no trace and attaches in seconds

RTurner: "

"There is a katadyn one with a blue bag. I’ve seen two different ones get backed up on weeklong trips to Bwca. I’m sure they could have been back flushed but my Platypus didn’t have any issue."

My katadyn base camp filter clogged after 6 days in the BWCA. If we were going to stay any longer, we would have been boiling water. I always paddled out into the middle of the lakes to get the cleanest water I could before filtering. I can't find any way to back flush it. "

Those cannot be back flushed and plug fast. I think you can remove the filter and then use a sawyer mini(20.00) in line. I believe the lines are the same size. That would by far be your best solution. The mini is easily back flushed with provided syringe and is 1 micron rated and is supposed to last for 100,000 gallons. Mine is 6 years old and is going strong.

+1 for platypus gravityworks system
+1 for sawyer mini filter as a spare

andym: "We use a Sawyer with some MSR bags and some extra fittings and hose from the hardware store. Works great and makes life so much easier than pumping."

I really like my MSR Dromedary. I've been looking for a way to tie it in to the platypus system... please share andym! Was it a dromedary you bought the fittings for?

I had a bunch of MSR dromedary bags that I was using with iodine. I use one of those for the bottom bag.

I bought an MSR top bag for a gravity system to use with an MSR filter I had that could be used in pump or gravity mode but then decided to get a Sawyer filter instead due to discussions on this forum. The top bag has a nice snap in hose fitting that makes things easy. And it had a hose to dromedary fitting too.

I may have gotten some additional fittings for the Sawyer filter from REI and they were either Sawyer or maybe MSR fittings. And I filled out the system with fittings and hoses from the hardware store to make everything work together.

It’s been several years and so I don’t quite remember perfectly.

I prefer roll top bags over bladder style bags for my gray water and hard sided bottles over soft bladders for my potable water. Also use quick connect fittings and prefilters.

andym: "We use a Sawyer with some MSR bags and some extra fittings and hose from the hardware store. Works great and makes life so much easier than pumping."

This is what we do but I am frustrated with the Sawyer because it does not flush easily. Very frustrated in fact.

Ragged: "Platypus hands down, lighter and simpler than the competitors, bags are easier to fill, it just works great.



But they are all beer league compared to this bad boy, wouldn’t bring on a canoe trip unless it was a very large group but it sure is nice. CNC aluminum construction, solid brass CPC quick connects, stainless spigot, heavy duty 100mil buckets, bracket has been tested to 600lbs, leaves no trace and attaches in seconds


"

As always Ragged, your engineering prowess shines!

unshavenman: "Platypus."

To elaborate, I bring the 4L version. If it's two of us I bring one additional 4L Platy Water Tank and if it's a group of four I bring two 4L water tanks. When it's hung I don't seal the top of the dirty bag and just keep dumping water in. We never run out of clean water.

+Eleventy for Platypus. I haven't touched my Pur pump filter since the day I first used the gravity system in 2012. I usually back flush out of habit every time I go to refill the dirty bag, or if the process runs the dirty bag dry - it's important to keep as much air out of the filter as possible or it will slow down the filtering.

I am in the sawyer camp.

mgraber
Those cannot be back flushed and plug fast. I think you can remove the filter and then use a sawyer mini(20.00) in line. I believe the lines are the same size. That would by far be your best solution. The mini is easily back flushed with provided syringe and is 1 micron rated and is supposed to last for 100,000 gallons. Mine is 6 years old and is going strong."

thanks

andym: "We use a Sawyer with some MSR bags and some extra fittings and hose from the hardware store. Works great and makes life so much easier than pumping."

+1

I made mine using a 6l MSR Dromlite bag($25), a sawyer mini($20), some 3/8" tubing and 3/8" john guest valve(<$10) costs less than half of platypus gravity filter and and is less weight too.

My Katydyn basecamp died on two separate trips. This is a known flaw in the Katydyn filter and why they came out with a different filter.

I modified my basecamp by adding a Sawyer filter to the tubing. The modified filter works great.

I have gone to using purifiers/filter quite a while ago after an experience with a fellow trip partner. Owned a few, used more, made some at home. 2 years ago I was looking for a pump system that was simple compact and lite, and could be used as a gravity system. My First Need worked but was somewhat slow and heavy. Now I use a MSR Trailbase Everything I wanted but needed larger bags. It easily adapted to other size and makes of bags. Is fast in either method, field back-flushes simply, is the handiest on the trail filter I have.
My Sawyer systems, gravity and bottle, and First Need pump purifier, have sat on a shelf since then.

butthead

The system I built myself is the one I prefer. The only thing I might change is a different dirty water vessel. Maybe a dry bag with a bung instead of the current bucket with over-the-edge siphon.

mschi772: "I wasn't happy with any premade gravity system, so I built my own using:


Kent Systems Acrolene tubing and quick couplings (1/4")
Sawyer filter from the purifier bucket kit (0.02 micron)
Katadyn activated carbon filter (bottle adapter)
MSR dromedary bags for filtered water (10 liter)
12 liter collapsible bucket for dirty water



I did not cut a hole in the bucket; I just run the line over the edge of the bucket and use my syringe (or, honestly, my mouth) to suck on the CLEAN side of the filter to start the flow. It takes no time to filter 10 liters. The bucket fills quickly compared to systems that use enclosed bags for dirty water, and it can be used for so much more; I store the whole system in the bucket (after rinsing the bucket with clean water) when packed. The whole thing disassembles into pieces quickly due to the quick couplings, and I even have some coupling plugs to put on each end of the filter to keep it from leaking when I pack it up between sites. The adapter cap that attaches the hose directly to the dromedary bag is your standard "Nalgene thread," so this system will attach to just about anything.


Obviously it could be whatever capacity you prefer, and you could choose a lighter bucket/bag and use a Sawyer mini instead, but for my larger basecamping group I love the large capacity and durability of this. I LOVE these dromedary bags; they're so bombproof! Shout-out to Kent's tubing for its insane durability, too--this Acrolene stuff is crazy tough.


It's plenty light for me, and if I need to shave weight, I use my Sawyer mini, leave the charcoal part at home, and switch to a smaller silnylon bucket and a smaller clean bag or just no clean bag and tap the system for water as needed.


The charcoal filter is unnecessary, but the girlfriend is very picky about water, so I added it so that any strange colors or tastes would not have to be an issue for her, and I have to admit that water from this system is amazing, and that charcoal filter does deserve some of the credit.


I am considering cutting a hole in a bucket and adding one of Kent's shut-off bulkheads (only flows when connected to another coupling) to it so that it can still function as a bucket but siphon-starting would be a thing of the past.


The photo below is the best I've got of the system in action, but it was taken when a friend attached their camelback to fill it instead.



Kent Systems
MSR Adapter for tubing to the bag
MSR Dromedary bag
Sawyer filter
Katadyn carbon cartridge
Bucket
"

Mad_Angler: "My Katydyn basecamp died on two separate trips. This is a known flaw in the Katydyn filter and why they came out with a different filter.


I modified my basecamp by adding a Sawyer filter to the tubing. The modified filter works great."

Hey Mad....I just picked up the 3L Katydyn and now I am nervous....do you know when the filter fix came out? thinking I want to order one as a just in case because it sounds like a when not if it fails.

unshavenman: "

As always Ragged, your engineering prowess shines!"

Thanks, this years glamping extravaganza will be dealing with those heavy Rotomolded coolers. It’s ironic, they are bear resistant but even the generic RTICs cost enough that you don’t want a bear chewing on them so we end up putting them in the lockers anyways. Well dragging a 45lb cooler, with 40lbs of ice and 10lbs of food out really sucks! That problem will be a thing of the past, at least for me:)

Selfsuffi: "

Mad_Angler: "My Katydyn basecamp died on two separate trips. This is a known flaw in the Katydyn filter and why they came out with a different filter.



I modified my basecamp by adding a Sawyer filter to the tubing. The modified filter works great."

Hey Mad....I just picked up the 3L Katydyn and now I am nervous....do you know when the filter fix came out? thinking I want to order one as a just in case because it sounds like a when not if it fails."

Essentially what Mad Angler did was dump the actual Katadyn filter proper and replace it with the Sawyer filter, but kept the Katadyn bag. If you just bought the Katadyn filter and can return it for a Sawyer or Platypus, I would do it.

Build your own. Its a fun project and works much better

Ardwich: "Build your own. Its a fun project and works much better "

I did a test with a similar roll top bag and it was very evident the material was adding a strong plastic taste to the water, have you ever noticed that?

sawyer for me. has worked great. as mentioned stay away from katadyn, mine plugged after 2 days.

Ragged: "

Ardwich: "Build your own. Its a fun project and works much better "

I did a test with a similar roll top bag and it was very evident the material was adding a strong plastic taste to the water, have you ever noticed that?

"

I ordered a couple of these same bags back when first looking for better in-camp water storage to replace our 5-gal Reliance collapsible jugs. Not necessarily for a gravity setup, but with thoughts of that perhaps in the future. Water smelled and tasted so bad - plastic/chemical odor and taste - that I think I threw them out. Or, maybe sold them here ?? If I recall, they are labelled "Not For Drinking Water."

We have the sawyer 4L gravity system and it works great. Never had any issues just backflush after every trip. I would prefer to have a dirty water bag that completely opens on one end similar to the platypus system or the katadyn 3L system. I think there is also a CNOC bag that is similar. If the sawyer bags ever need replaced that is likely what we would use, just for ease of filling.

Also picked up the katadyn befree filter last year and used it for day trips. Works really well with a very fast flow rate.

Ardwich: "Build your own. Its a fun project and works much better "

Seems to be disagreement with the materials you choose but I like your DIY project, thanks for the photo.

It bothers some people that I choose to hydrate my oatmeal with hot water in a freezer bag.

Nope. 5 years with the same bag. Water has no taste at all.

Never any issue for my group and myself. We have filtered hundreds of gallons through the thing with no taste or odor issues. Works phenomenal. Wouldnt want anything else.

IndyCanoe: "We have the sawyer 4L gravity system and it works great...I would prefer to have a dirty water bag that completely opens on one end..."

Agree. That led us to the Innate Aqueduct Water Transporter, a very difficult item to find and most recently purchase from MEC in Canada. We head out to deeper, cleaner water, fill it through the roll-top opening, and use it back in camp to fill the Sawyer grey bag.

Ardwich: "Never any issue for my group and myself. We have filtered hundreds of gallons through the thing with no taste or odor issues. Works phenomenal. Wouldnt want anything else. "

Good deal. Wish I could say the same for the ones we bought.

+1 for the MSR Trailbase.

butthead - Would be great to see your mods!

butthead: "I have gone to using purifiers/filter quite a while ago after an experience with a fellow trip partner. Owned a few, used more, made some at home. 2 years ago I was looking for a pump system that was simple compact and lite, and could be used as a gravity system. My First Need worked but was somewhat slow and heavy. Now I use a MSR Trailbase Everything I wanted but needed larger bags. It easily adapted to other size and makes of bags. Is fast in either method, field back-flushes simply, is the handiest on the trail filter I have.
My Sawyer systems, gravity and bottle, and First Need pump purifier, have sat on a shelf since then.


butthead
"

bri: "+1 for the MSR Trailbase.


butthead - Would be great to see your mods!
"

"

MSR Trailshot-Pump from canoe?

MSR Trail Shot

butthead

unshavenman: "Platypus."

yep, me too!

schweady: "
Good deal. Wish I could say the same for the ones we bought.
"

Yeah same here, I think mine were Outdoor Products brand, maybe Ozark Trail. Most of those types are pretty known for leaching taste, if it smells like plastic when you buy it you will likely taste it.

Katadyn. Has worked as advertised.

Selfsuffi: "

Mad_Angler: "My Katydyn basecamp died on two separate trips. This is a known flaw in the Katydyn filter and why they came out with a different filter.



I modified my basecamp by adding a Sawyer filter to the tubing. The modified filter works great."

Hey Mad....I just picked up the 3L Katydyn and now I am nervous....do you know when the filter fix came out? thinking I want to order one as a just in case because it sounds like a when not if it fails."

Use the BWCA search. But the idea is very simple. Just buy the Sawyer micro filter. When your Katydyn filter dies, just insert the Sawyer filter in the basecamp drain tube. I cut the tube and sandwiched ther Sawyer filter about a foot below the Basecamp bag.

You also have to remove the outer shell of your Katydyn filter:

Mad_Angler: "

Selfsuffi: "

Mad_Angler: "My Katydyn basecamp died on two separate trips. This is a known flaw in the Katydyn filter and why they came out with a different filter.



I modified my basecamp by adding a Sawyer filter to the tubing. The modified filter works great."

Hey Mad....I just picked up the 3L Katydyn and now I am nervous....do you know when the filter fix came out? thinking I want to order one as a just in case because it sounds like a when not if it fails."

Thank you!


Use the BWCA search. But the idea is very simple. Just buy the Sawyer micro filter. When your Katydyn filter dies, just insert the Sawyer filter in the basecamp drain tube. I cut the tube and sandwiched ther Sawyer filter about a foot below the Basecamp bag.


You also have to remove the outer shell of your Katydyn filter:
"

Had good results with a Platypus gravity system for several years now. Also use a MSR dromedary bag for extra storage. Katadyn pump for backup.