Platypus - Big Zip EVO Reservoir - 3 Liters

Category: Backpack

I used this bladder to go backpacking a couple times and it worked great. I whipped it out last weekend to hike Mt. Saint Helen's and the quick connect had a crack right up the seam. Lucky I noticed it and filled up a couple Nalgene's instead. I went to REI and they replaced it. I am hiking Mt. Rainier tomorrow, I guess I better bring the Nalgene's. I am really dissatisfied with product.

I bought this to replace an original Big Zip reservoir. The two biggest improvements that alone make it worth the upgrade are the improved bite valve and the relocation of the hose attachment point to an area higher on the bag. The bite vale really does make a difference. Getting water out of this is no longer the reverse of inflating a NeoAir. The use of an extension to move the drinking hose attachment point to the top of the bag is genius. It allow you to put the filled bag in your pack and then route the hose through any guides on your shoulder strap before attaching it to the bag. It's a lot more convenient. I'm not sure how this affects cleanabilty. I use only water and rinse and then store the reservoir and hose in the freezer (in a OP bag) between uses. One thing I'd like to see is for Platypus to include their bite valve cover. It can't be more than $1 to produce and given the price of this reservoir, should really be standard equipment.

From the very first fill of water, this reservoir has performed as advertised with no plastic taste. My wife is very particular about her water it pasted her taste test. I would highly recommend this product to anyone who wants their tasteless.

New to hiking and this the first hydration reservoir I've ever used. I put the 3L reservoir in the laptop compartment of an old North Face backpack while doing longer day hikes last week in Rocky Mountain National Park. I have lower back issues so I wanted something that would more evenly distribute the water weight throughout the day compared to starting out with two full Nalgenes, which would inevitably make one side of the pack more lopsided. The large opening made it very easy to fill, clean, and dry. Also loved that I could detach the bag from the hose so that I but did not have to redo the hose positioning on the shoulder strap in the morning (I would detach the bag, fill it up the night before a hike, stick it in the fridge and just reattach the the bag to the hose before heading out). Never had any issues with leaks for ~40 miles of hiking. Considering the price of the 1.5L and 2L are within a few dollars, I'd say go with the 3L if your pack can fit it and you can always just fill it up less than 3L. I'd rather have a few sips leftover than run out early!



Will the 3 liter Platypus work with Osprey Kyte 46?

​Yes, this reservoir will work well with the Osprey Kyte 46.


Hi there -  Will this work with a Gregory Palisade 80? Thanks!

​Yes, this reservoir will work in the Palisade 80 pack.


Is this compatible for use with a pfd?

This reservoir is compatible with backpacks. Using this with a PFD would depend on the features of the PFD.


Will this fit in a Osprey Daylite pack?

​No, the Big Zip 3 liter is too large for the Daylite pack.


Can I freeze water in the reservoir?

Yes, but be careful not to over-fill the reservoir (no more than ¾ full) or it may expand and damage the bladder. For the best results, purge all air and lay the reservoir flat in your freezer.


Water has strong taste. Same water from a bottle is fine. Don’t know how to solve. Also need instructions on how to clean the tubing.

Check out our Expert Advice article on how to clean a hydration reservoir. Hopefully a good cleaning will eliminate the taste you are experiencing.

Jay Ray

Hi Hi just wondering where the clip is on this to keep it upright and connected in a hydration compatible pack... I was looking at the photos, but I can't find it. I see the slide device for loading water, but surely one can't use this as a clip...

This reservoir does not come with a hanger; we recommend the Platypus Big Zip EVO Reservoir Hanger for packs that have an interior hang loop:


If I boil my water what temperature should the water cool to before I pour it in? Is there a risk of the bag melting or failing if I purify my water through boiling? Thanks!

Ideally, you will let the water cool to a temperature that allows you to hold the reservoir in your bare hands without any discomfort. Platypus does not offer a temperature value for this question.


Does the bite valve attached to the pack magnetically, or will I have to buy a new bite valve?

Thank you for your question! This has a regular clasp style hose attachment, however, the hose magnet can be swapped from a prior hose to also work with the EVO reservoir.


Is this bladder compatible with iodine and/or chlorine dioxide purification tablets?

Yes, just make sure you clean the reservoir after each use with any chemicals.


What bite valve cover do you recommend for big zip evo? 

​The Platypus Bite Valve Cover will be perfect.

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