I am currently trying to decide between the msr gravity system or the platypus gravity system. I am open to other system but these seem to be the best. Any experience with these and suggestions?

I have an MSR because a friend had used one on a trip and I liked it. I like mine but I don't love that I have to backflush it as much as I do. It's almost like it needs to be "primed" with a little backflush before it'll filter quickly; so much so that I try to keep a little water in the clean side at all times so that when I gather new water I can just backflush a few ounces to get it started.

[edited out a line about platypus]

It does seem like there are more innovative and more effective filters. I'm not going to change to something else right now, but if I were buying new I might look at the clever Sawyer setups some are using.

I have the Platypus and am very happy with it. Backflush is super easy way to keep clean, and I like the clear bags. Have been very dependable and easy for me. I would get the same one again tomorrow without hesitation.

I'm sorry, did you say, "Sawyer"?

Yes, everyone will pull you in different directions, but I think you will want to give the many options that Sawyer products offer a good, hard look.

TominMpls: "I haven't used the Platypus but I think I recall it having more issues, not fewer."

Are you sure you are not thinking of Katadyn? I've definitely heard of more problems with that one, and the reviews on REI and Amazon are pretty so-so.

Jaywalker: "

TominMpls: "I haven't used the Platypus but I think I recall it having more issues, not fewer."

Are you sure you are not thinking of Katadyn? I've definitely heard of more problems with that one, and the reviews on REI and Amazon are pretty so-so. "

Oh yes, you're right. Sorry for the confusion. I'll edit that out of my original response.

DontPanic: "I am currently trying to decide between the msr gravity system or the platypus gravity system. I am open to other system but these seem to be the best. Any experience with these and suggestions? "

I have a few water filters including a MSR Waterworks, Sawyer Squeeze and Sawyer Mini. I had the opportunity to use the Platypus 4L gravity filter a couple years ago on a 3 day backpacking trip which included 12 Boy Scouts and 3 adults. The Platypus system made all our other filters unnecessary. It filtered so fast and back flushing was so effortless that after the first water stop, we relied exclusively on the Platypus system. I bought the Platypus 4L Gravity system with my very next REI 20% off coupon and have not used any other filter since. When solo hiking, I leave the clean bag home and filter directly into my water bottles.

I have a Platypus 4L system, love it. Regarding the need to prime/backflush every time to get flowing properly, if you don't allow the filter to run completely dry then this will avoid it. I will either clamp it closed before the dirty bag gets totally emptied or run just enough back thru the filter from the clean bag to fill the hose with water. The black plastic nipple that came with the filter is perfect for capping the clean side between uses & creates an airlock that won't allow the filter to run empty if its carefully handled.

I have an MSR gravity and love it. Do not see the need for a second bag; extra weight.

DontPanic: "I am currently trying to decide between the msr gravity system or the platypus gravity system. I am open to other system but these seem to be the best. Any experience with these and suggestions? "

MSR has 2 gravity systems, TRAIL BASE GRAVITY FILTER SYSTEM is new and can be used as a hand pumped trail filter also.

MSR AutoFlow and the GravityWorks which seems a more complete setup with the same filter.

I have a home made Trail Base built from the Trailshot and used it last year. Very happy with it.

butthead

We have the Platypus 4L Gravity Works. Simply a great system. No issues and minimal back flushing. I would buy another one tomorrow.

We have the Platypus Gravityworks 4L and have used it primarily for backpacking so far. We plan to use it on our upcoming BWCA trip. I love it and have absolutely zero complaints with it. Yes you have to backflush it every once and while, but it's very easy to do and it's not unique problem to the Gravityworks or anything. You have to backflush all of them. To backflush all you do is lift the clean bag above the dirty bag to reverse the flow for a few seconds.

Are you referring to the MSR Trailbase? If so I'm sure you won't be disappointed in either system you get. But after looking it at it I don't think we would purchase it, since it's a 2L system and weighs more than our 4L. I also don't seeing ourselves using the "trailshot" part of it.

After taking a look at other current options from Sawyer and Katadyn I would 100% take the Platypus Gravityworks again.

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

I have the MSR gravity filter system but I've seen the platypus in action and it's a great system as well.

mirth: "I have a Platypus 4L system, love it. Regarding the need to prime/backflush every time to get flowing properly, if you don't allow the filter to run completely dry then this will avoid it. I will either clamp it closed before the dirty bag gets totally emptied or run just enough back thru the filter from the clean bag to fill the hose with water. The black plastic nipple that came with the filter is perfect for capping the clean side between uses & creates an airlock that won't allow the filter to run empty if its carefully handled."

This is exactly right. The platypus filter can sort of "vapor lock" when the filter runs dry. Bubbles in the filter try to exit up against the flow and prevent any liquid from making it through the filter. I alway prime the filter with tap water before I leave home and keep the filter full by clamping off the tubing before and after anytime I take the bags off.

You can also keep some filtered water on the clean side when you fill the dirty bag. Then backflush the clean water to prime the filter and the system should work without any trouble.

This matches what I've experienced with my MSR, good description. I guess it's just a characteristic of this type of filtering. The quick prime is fine, it's just frustrating to have to do it.

TominMpls: "This matches what I've experienced with my MSR, good description. I guess it's just a characteristic of this type of filtering. The quick prime is fine, it's just frustrating to have to do it."

It would be nice if the priming idea was incorporated into the filter design. I use plastic hose clamps to pitch the tubes closed. The manufacturer should add manual check valves to the system to hold the water in the filter.

I'd also like a dedicated clean side outlet on the platypus, either as part of the clean bag (like the MSR) or just a separate tube. Taking the tubes apart to get the clean water seems like asking for trouble.

I've had this "vapor lock" issue with my Platypus a few times. I'll hang my dirty water and start to set up my tarp. After about five minutes, I look over at my water and its either done or there's just a little done. If just a little is done, I put the dirty on the ground, raise the little bit that's clean and back flush a little. So far every time this gets the bubbles out and the water runs fast. Either way, by the time my tarp is up, my water is done.

Jaywalker: "I've had this "vapor lock" issue with my Platypus a few times. I'll hang my dirty water and start to set up my tarp. After about five minutes, I look over at my water and its either done or there's just a little done. If just a little is done, I put the dirty on the ground, raise the little bit that's clean and back flush a little. So far every time this gets the bubbles out and the water runs fast. Either way, by the time my tarp is up, my water is done. "

This is how I end up running it some times, too. Get a little clean water and reverse the flow. The air easily leaves the clean side and ends up in the clean bag when you flow in reverse. The reverse flow gets the air out of the dirty side. I tap the filter a bit to help the bubbles get moving.

I think it's a function of the way the filter is constructed. The hollow tube loops on the dirty side can somehow be effectively blocked by air and surface tension. The bubbles don't want to leave and keep water from entering. The clean side is just a bunch of tiny holes where the tubes end and the incoming water easily displaces most of the air.

Last fall I tried the MSR system, and functionally it's great, but like others have said it requires some backflushing, and it can seem to get a vapor lock in it. I had to dissassemble ours several times on the trip to get it working again. I spent a lot as much time filtering water as I did cutting wood......it was ridiculous. Didn't really save us much free time....BUT when we got water it was pretty high quality:-).

Air/vapour lock does not affect the MSR Trail Base system, the filter is in a squeeze bulb pump fed with a one way valve. Set it up give it a squeeze or 2 and the water is flowing!

butthead

butthead: "Air/vapour lock does not affect the MSR Trail Base system, the filter is in a squeeze bulb pump fed with a one way valve. Set it up give it a squeeze or 2 and the water is flowing!
butthead"

That's probably the nicest gravity system available right now, and worth the premium cost. For those of us who own an older system, just keeping the filter full solves most of the issues.

Built my own with the sawyer filter.. worked like a charm other than I forgot my syringe to back flush, so on day 4 it got a bit slow. But the filter was like 25 bucks and the rest of the materials maybe another 15 I cant complain for what I ended up with. but gravity systems win hands down 8 days a week. no more standing in the lake pumping water... that is just dumb now

A cheap and very light (8 oz) system is the Sawyer 1 gallon gravity system. We have it and like it but it is not heavy duty, large , or the easiest to fill but works well and Sawyer filters can be back flushed and used many, many times.

I've got a home brew Sawyer system with some MSR parts (dirty bag and dromedary bag on the bottom. But that new Trailbase looks mighty nice. Hmmm. The ability to pump a little on the go is nice. Of course, the Sawyer squeeze allows that. But pumping to get air out of the filter is also nice. Now where is that credit card?

Ok, with so many responding with their positive experience with this filter type, I have to ask how you can keep these filters flowing. I have stated in several previous threads about my past experience with these types of filters. I have used MSR, Platypus and Sawyer, and I could get none to last more than 3 or 4 trips. Some did not last through a single trip. After 3 days the flow is greatly reduced, and backflushing does not solve the issue. In fact, it comes to a point where you cannot generate enough pressure to get flow through the filter. In fact, once home I can try using the faucet adapter that Sawyer provides for backflushing, and sometimes I cannot hold the adapter on the faucet as the pressure is too great and there is NO flow through the filter. Sawyer customer service has told me it has to do with the tannin in the water, and I can vouch for the fact that it is not a particulate issue. I tried their suggestion of soaking the filter in a hot water/vinegar soultion, to no avail. Since it is near impossible to avoid water with tannin in the BW, how do you keep these filters usable?

Are you collecting your water away from the shore line? I have used a Sawyer gravity system for 4-5 years. We do 7-8 day trips, and do not have a problem. After the trip I backflush and let. Dry completely before storing.

I have an MSR and like it. It is slower than a pump, but that has yet to present any real issues. While I agree that it seems to need backflushing more often than other filters I have used, I like that it has no moving parts.

bpaddle: "Ok, with so many responding with their positive experience with this filter type, I have to ask how you can keep these filters flowing. I have stated in several previous threads about my past experience with these types of filters. I have used MSR, Platypus and Sawyer, and I could get none to last more than 3 or 4 trips. Some did not last through a single trip. After 3 days the flow is greatly reduced, and backflushing does not solve the issue. In fact, it comes to a point where you cannot generate enough pressure to get flow through the filter. In fact, once home I can try using the faucet adapter that Sawyer provides for backflushing, and sometimes I cannot hold the adapter on the faucet as the pressure is too great and there is NO flow through the filter. Sawyer customer service has told me it has to do with the tannin in the water, and I can vouch for the fact that it is not a particulate issue. I tried their suggestion of soaking the filter in a hot water/vinegar soultion, to no avail. Since it is near impossible to avoid water with tannin in the BW, how do you keep these filters usable? "

I've used my gravity system exclusively in the BW and have never had this problem. I backflush about a 0.5 to 0.75 liters for each full dirty bag. I have a syringe, but I've never used it in the field. I also have a mesh prefilter, but it doesn't stop anything smaller than .020".
I've got a bit of a frankenstein at this point: it was originally a platypus 4L, but I have used both the platypus filter and a sawyer mini filter. The sawyer seems faster.

Post trip I run distilled water through the whole system, forward and backwards, with a little bleach at first. Probably a gallon of distilled water total. Then I air dry and put away for storage. The platypus filter seemed to get a bit slowed by what I assumed where mineral deposits after several trips, but the distilled water soak has fixed that issue.

Frenchy: "Are you collecting your water away from the shore line?..."

Probably the most important step. Many feel that filtering negates the need to worry about collection source. Filter life is greatly extended by collecting water that starts out as clean as possible. My Sawyer 4L system (purchased before everyone pioneered the DIY setups) is going strong with a field backwash every day or two and a heavy backwash at the faucet when back home. Follow the directions that came with it or online for use of bleach solutions, wincing, drying, and storage and it should theoretically last a lifetime.

Have been using Sawyer for 3 years now, total of 42 days in ,and am on the same 2 filters.

OCDave: "

DontPanic: "I am currently trying to decide between the msr gravity system or the platypus gravity system. I am open to other system but these seem to be the best. Any experience with these and suggestions? "

I have a few water filters including a MSR Waterworks, Sawyer Squeeze and Sawyer Mini. I had the opportunity to use the Platypus 4L gravity filter a couple years ago on a 3 day backpacking trip which included 12 Boy Scouts and 3 adults. The Platypus system made all our other filters unnecessary. It filtered so fast and back flushing was so effortless that after the first water stop, we relied exclusively on the Platypus system. I bought the Platypus 4L Gravity system with my very next REI 20% off coupon and have not used any other filter since. When solo hiking, I leave the clean bag home and filter directly into my water bottles.



"

+1 we had our own gravity type system we had made from a sawyer mini and switched to platypus and the difference is astounding. platypus= nice :)

I really like the Katydyn basecamp to Sawyer conversion...

I love the Katydyn basecamp bag. It is very big and easy to fill. I keep looking and I do not see another bag that is quite as good.

I love the Sawyer filter. It is small, light and flows quite well. I had a group of 9 in the BW . I only had to backflush every few days. And backflushing was fast and easy.

I made my own also and it was much less expensive and works great. Also, it is very light. I use the Sawyer filter on mine.

Jaywalker: "I have the Platypus and am very happy with it. Backflush is super easy way to keep clean, and I like the clear bags. Have been very dependable and easy for me. I would get the same one again tomorrow without hesitation."

i started with msr pump, good working filter, but the platypus is what i use now.
my go to filter.

I have have had the Gravity 4 liter system for 3 years. Buy it. Im still on my first filter. It is better than everything on the market for a basecamp water system. I think it weighs like 13 oz. Easily can keep 8 people hydrated. As your trip goes on you find you will have to back flush more often. Super easy to do, just switch the bags where they are hanging. I also bring one of those small plastic plungers from the Sawyer mini and that will back flush it and clean it out super great to get water flowing fast again.

I also highly suggest the Katadyn Befree for purifying water on the move. The flow on it is incredible.

I also made my own with a sawyer filter and 2 gallon bag. 2008 and ten years later no problems. I has seen a lot of tannin stained water and water is dipped well offshore. I flush it on faucet when I get home.