Neptune Series™ 4.0L Water Filter System

Neptune Series™ 4.0L 

Water Filter System


Go ahead, invite the whole crew. With the largest carrying capacity in the Neptune family, our 4.0L system is built for heavy-lifting. Just fill and leave around base camp to meet all your water needs.

The clean reservoir comes with an extra quick-disconnect port so you can snag a burst of water to brush your teeth or fill your camp cup – without disturbing your whole set-up.

What's Included:

• Water Filter

• 4.0L Reservoirs (Clean & Dirty)

• Tubing Kit

• Shutoff Clamps (2)
• Velcro Straps (2)

• Hanging Straps (2)

• Spare Pre-filters (5)

• Quick Access Spigot

• Collapsable Storage Bag


  • Choose Your Adventure. Our modular system adapts to your excursion. Our 1.0L, 2.0L, and 4.0L products are 100% interchangeable, so you can switch it up every time you hit the trail.

  • No Pumping, No Problem. Hands-free filtration lets gravity do its thing. The gravity-fed filtration system pulls unfiltered water from the dirty reservoir into the clean reservoir – all you have to do is kick back and relax.

  • Lightweight, Heavy-Duty. All Neptune Series™ systems are built to tuck away – or take a beating. The ultra-light collapsible design saves precious pack space, while durable TPU material holds up under pressure.

  • Dummy-Proof Disconnects. Quick-disconnect ports detach in a snap so you can fill and swap reservoirs without getting tangled in your setup. Horizontally-angled ports enable maximum roll-up-ability at go time.

  • No Mess or Missing Pieces. All reservoirs feature a reinforced plastic closure piece for a tighter seal and total reliability. The closure piece tethers to the reservoir, so wherever you go – it comes with you.



CAPACITY - 4.0 Liters

DIMENSIONS - 8 x 19.5 in.

WEIGHT - 235 g / 8.28 oz (Both Reservoirs)

MATERIAL - Thermoplastic Polyurethane (TPU)


LIFESPAN - 5000 L / 1320 gal.

FLOW RATE - 1 L/min

WEIGHT - 55 g / 1.94 oz (dry)

DIMENSIONS - 5.5 x 1.5 in.

FILTER MEDIA - Hollow Fiber Membrane


99.9999% Bacteria

99.9% Parasites

99% Turbidity

MATERIAL - ABS, Polypropylene, Silicone

BPA Free

PORE SIZE - 0.1 Microns

Fast &  Shipping 

Lifetime Warranty

Money-Back Guarantee

Cleaning & First Use

Our reservoirs are manufactured to high standards and are made from taste-free food grade TPU material. However, it's always a good idea to clean your reservoir when you first receive it, and after each use.

Best cleaning methods:

• Cleaning Tabs

• Baking Soda - Mix 2 TBSP of baking soda per 2 liters of water. Add the mixture to your reservoir, shake it to mix the ingredients, let sit for 30 mins, then rinse/dry thoroughly.

• Soap & Hot Water

• Bleach - Fill your bladder with water, mix in 1 TBSP of bleach per 2L of water. Let sit for 30 mins, then rinse/dry thoroughly.

Drying & Storage

Whisk - Place a whisk inside the reservoir and lay it on it's side to dry.

Hanging - Hang the reservoirs over a shower rod overnight.

Freezer - Roll up your reservoir and store it in the freezer. Rinse with clean water before next use.

Can I order replacements? 

Of course! We sell individual reservoirs (clean and dirty in all capacities) as well as a replacement filter set here. 

Do you offer a warranty or money-back guarantee? 

Yes, we offer a 30-day money back guarantee, and a lifetime warranty on all of our products. Material or manufacturer defect? Our 100% lifetime warranty has your back. Lost or beat-up pieces? All Salado Outdoor components are sold separately for easy, affordable replacement. Don’t sweat it, we’ve got you.

What are the reservoirs made from? Are they BPA free?

The reservoirs and components are all BPA free.

Our reservoirs are made of FDA food grade Thermoplastic Polyurethane (TPU) material, which is BPA free, durable, lightweight, and can be stretched up to 750% it's original size. It was an obvious choice for us, and you'll find it to be dependable in the field for many years to come.  

The seals and welds in our reservoirs are made using a thermal binding process. The strength of the bonds can withstand up to 440lbs of pressure, all without using harmful chemicals or glue.

Does the filter need to be cleaned after use? 

We recommend back flushing your filter with a mild bleach solution after use. To back flush, fill a water bottle with clean water (use a 1 Liter SmartWater bottle, collapsible water bag, or any standard water bottle) and screw your filter's "out" side onto the bottle. Squeeze the entire liter of water through your filter. Then, squeeze 1 Liter of clean water through your filter. This process should keep your filter clean, and ready to use for many years to come! 

Related Products

warehouse manager salado outdoors

Meet Claire, our warehouse manager

About Us

Phoenix, Arizona

We’re Landon and Katrina, and we founded Salado Outdoors at our kitchen table in the spring of 2020 – yep, that spring of 2020. We both grew up hiking, camping, and getting dirty outside. We operate Salado Outdoors from the same place we founded it: our home. We pack and ship every product ourselves. If you experience an issue with your product, we’re the ones that answer the call. We don’t just sleep under the stars; we shoot for them too. Our goal is to simplify getting outside with a full line of flexible, hard-working adventure gear. For hardcore survivalists, afternoon ramblers – and every explorer in between.