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Hands-on Gear Review

Platypus Big Zip SL Review


Hydration Bladder

  • Currently 4.2/5
Overall avg rating 4.2 of 5 based on 3 reviews. Most recent review: March 29, 2015
Price:   $35 List | $37 online
Compare prices at 1 resellers
Pros:  Good value, easy to clean, can switch out the hoses with other brands.
Cons:  Not the easiest bit valve to drink from.
Manufacturer:   Platypus
Review by: Chris McNamara ⋅ Founder and Editor-in-Chief, OutdoorGearLab ⋅ March 29, 2015  
This is a solid performing hydration bladder that is easy to clean and relatively light. The zip closure is intuitive and fast to use. The quick release system is compatible with many other hydration bladders as well. This was a contender for our Best Buy award but we ultimately went with the CamelBak Antidote Reservoir because we like how easy the Antidote is to drink from and fill. If you really like the zip top opening we also recommend checking out the Geigerrig Hydration Engine.

New Version Available - Mar 2015
The Big Zip SL has been replaced by a newer version called the Big Zip LP which has a slimmer profile (the "LP" stands for "low-profile"). The Big Zip LP is available in 1.5, 2, and 3 liters. More information on the LP is provided below.

RELATED: Our complete review of hydration bladders

  • Photos
Click to enlarge

OutdoorGearLab Editors' Hands-on Review

New Version of the Big Zip vs. Older Version

In 2015, Platypus came out with a new version of the Big Zip SL, called the Big Zip LP to replace the Big Zip SL.

The photo below shows the older SL on the left, and the new LP on the right.
Click to enlargeClick to enlarge 

Platypus provided us with the following information about the comparison between the SL and LP.

"SL stands for super light and was introduced as the lightest bladder system available at the time. We continued to evolve and make improvements to our design and in 2014 replaced the SL with the LP. LP stands for low profile. This new bladder is the same light weight design as the SL model but has a new baffle down the middle of the bladder that keeps it from bowing out when filled making it 30% slimmer while providing the same total volume as the previous model."

We haven't done a full review of the Big Zip LP yet, but it Platypus describes it as 30% slimmer and you can see in the photos above they've increased the width of the bladder to reduce thickness. The "LP" stands for low-profile, indicating this new key change in this version. The slimmer design may make it fit easier in your pack, and leave more room for your other stuff. It isn't so different from the Big Zip SL it replaces, and so we think our SL review below will still give you a pretty good feeling for the newer Big Zip LP. The price remains $35 list.

Big Zip SL Review

This reservoir stands out because it has a large opening that is easy to clean, fill and lends itself to some innovative uses. For example, it is easy to use this as an ice pack if you are injured and have trouble finding a Ziploc bag.

Performance Comparison

Click to enlarge
Platypus Big Zip SL water reservoir
Credit: Platypus

Ease of Filling

This scored in the middle for ease of filling. It is easy in a deep sink. However, in a shallow sink the zip top is a little tricky at times.

Click to enlarge
The Geigerrig and Platypus zip style closures are hard to get completely full in a shallow sink. The CamelBak (below) is easy.
Credit: Chris McNamara


We scored this high for durability because we have not encountered any leaking problems and not found many reports online through user reviews.

Ease of Drinking

This is the only reservoir where we really felt like we had to suck hard at times to get water out. Luckily, the quick-link tube attachment is compatible with other hose systems. In our case we took the CamelBak Bite Valve, which is our favorite non-pressurized bite valve, and swapped it out.


This is one of the lighter hydration bladders we tested. But if your main objective is going ultra lightweight, we recommend the Platypus Hoser or the MSR DromLite.

Ease of Cleaning

The Big Zip opening means that it is easy to get just about any scrub brush or sponge into the main compartment. It is also very easy to dry this out. We did not see anywhere on the website that you can put this in the dishwasher. That is one big advantage of the Geigerrig Hydrations Engine - just toss it in the dishwasher and you are good to go. Cleaning the tubes is just as challenging as with all hydration systems. Just about any kitchen brush will get into the main reservoir. However, to clean the tube we recommend getting the Platypus Play Cleaning Kit.

Best Applications

We mainly use the 2 L version because the hydration bladder and fits perfectly inside our super old-school CamelBak hydration pack. This reservoir really shines if your backpack or hydration pack has a very narrow compartment for a hydration bladder.


At $30, this is in the good value range for hydration bladders. We expect this to have good long-term durability value.


We really like this hydration bladder. However, it didn't quite rise to capturing any awards. It is a good all-around reservoir but we didn't particularly like the bite valve and it lacks some of the features of the other award winners.

We have heard people rave that the Platypus does not have the "plasticy" taste that CamelBak and other hydration reservoirs do. However, in our test we found no giant difference in the way all the reservoirs tasted, especially over longer term usage.

Other Versions

Platypus Hoser
Click to enlarge
  • Cost - $25
  • Weight - 3.8 oz
  • Made of a similar material but does not have the big opening
  • Lighter weight but not as easy to fill and not as easy to clean


Cleaning Kit
Click to enlarge
  • Simple tools to keep bottles, bladders and hoses clean
  • Especially useful if using hydration mixes
  • Cost - $13

Chris McNamara

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OutdoorGearLab Member Reviews

Most recent review: March 29, 2015
Summary of All Ratings

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100% of 1 reviewers recommend it
Rating Distribution
2 Total Ratings
5 star: 50%  (1)
4 star: 50%  (1)
3 star: 0%  (0)
2 star: 0%  (0)
1 star: 0%  (0)
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   Aug 18, 2014 - 11:09am
Chudak · Climber
I am surprised to see this only gets three stars as I can find no fault with it. Yes, sometimes the bite valve is a little finicky but I would
rather that than one that leaks. The quick disconnect is really well made,
as is everything else. I'm going to get another one for the wife as she has
the non-zip Platypus which is fine for local jaunts but the Big Zip is much
better for backpacking (duh).

Bottom Line: Yes, I would recommend this product to a friend.
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Apr 21, 2013 - 10:00pm
spidey · Climber · Berkeley CA
Great choice for all around use. I've tried the camelbak reservoirs and found they leak faster and the water tastes more plasticky. Also they are harder to open and close - the big zip closure is easy to use and very secure, never leaks, very easy to fill and clean, etc. The ability to detach the hose at the base is a great feature - it allows you to leave your hose routed through the backpack while you fill the reservoir in a stream, sink, etc. The plastic is tough and as long as you don't abuse it should last a long time.

The bite valve works fine as far as i can tell…seems to leak less than camelbak's if you forget to twist it closed.
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Click to enlarge
Platypus Big Zip SL water reservoir
Credit: Platypus
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