The Brown Filter Bag

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5 reviews
Size: Personal
The Brown Filter Bag

The Brown Filter Bag is a canvas water filter that is easy to use and carry. It can be used on its own as a highly effective sediment water filter. 

The Brown Filter Bag is also effective when used in conjunction with a combined filter/purification system as a pre-filter to prevent clogging and extending the filtering life of the system.

Endorsed by British SAS survival legend John “Lofty” Wiseman. 

Available in two sizes: the personal size which holds up to 3 liters and the group size which holds up to 20 liters.

What is The Brown Filter Bag designed to do?

Making water safe is a two stage process. 1st Filtration 2nd purification.

The Brown Bag can be used for the first stage of making water safe, filtration. It is designed to filter turbid or dirty water. Turbid water is water with suspended sediment in it such as sand, mud, silt or organic matter.

It is essential to remove the sediment as it provides hiding places for water borne pathogens e.g. viruses, bacteria and parasites. If the sediment is not removed this is known to reduce the effectiveness of chemical purification treatments on these pathogens. In addition, if the sediment is not removed it can upset your digestive system.

What are the advantages of The Brown Filter Bag?

It is compact, lightweight, very durable, virtually unbreakable and it has an unlimited filtering capacity. Due to its compact size and lightness it can be easily stored and carried in your everyday essential kit.

Using your Brown Bag for the first time.

Prior to using your brand new Brown bag on your next trip, expedition or adventure it is essential that the new bag is broken in before. The fibers and weave of the canvas need to be loosened up and opened in order to maximize its performance.

How to break in your new Brown bag.

1. Saturate the bags in water, squeeze the water through the bags to unsure they are fully wetted.

2. Then be rough with them! Scrunch them up, massage and squeeze the bags. This will help to soften the canvas and open up the fibers.

3. Repeat the process 3/4 times allowing the bag to dry in-between.

4. You can also put the bags in the washing machine. Place in a clean washing machine on a cold rinse cycle with NO detergent and NO fabric softener. Always remove the paracord before placing in washing machine.

How to use the Brown Bag

Once you have found a source of water to be filtered make sure you have a suitable point to hang the bag from when its full of water. You can for example use a tree, tripod or vehicle.

1. Start by thoroughly soaking the bag in water, massage the water through the bag to insure it is saturated.

2. Fill the bag to the top with water to be filtered. It sometimes helps to use a cup to scoop water in to fill the bag to the top.

3. Allow the water in the bag to flow down to the stitched line that’s runs across the front of the bag approx. ¼ of the way down the bag. Do not collect this water, allow it to run onto the ground. This helps remove any debris on the outside of the bag and prevent it from dropping into your collecting pot.

4. The water will take between 5 and 10 minutes to pass through a personal size bag. A group size bag will take a number of hours to filter. When using a group size bag a good technique is to allow it to filter overnight, you will then have a stock of filtered water ready to disinfect the following morning.

5. Once the water has been filtered it must be purified. Although it may look clean it may contain pathogens which need to be removed by purification. The water can be purified by being brought to a rolling boil, adding chemicals or using a purification system.

After use and care

After each use turn the bag inside out and remove any built up sediment and debris. You can wash it out in clean water or allow the bag to dry out, this enables you to knock the dried sediment out once dried. A nailbrush is also effective for removing dried sediment. Make sure the bag is thoroughly cleaned and dried before storing away for your next adventure!


See more in the Bushcraft and Survival Magazine Issue 38.


  • Unlimited filtering capacity
  • A simple and effective way to filter out suspended particles and solids in turbid water.
  • Compact, Lightweight and very durable
  • Easily stored and carried in your everyday essential kit
  • Available in two sizes the personal size which holds up to 3 liters and the group size which holds up to 20 liters.

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All transit times are based on once your order ships.

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Once we receive your item, we will inspect it and notify you that we have received your returned item. We will immediately notify you on the status of your refund after inspecting the item. If your return is approved, we will initiate a refund to your original method of payment. You will receive the credit within the terms set forth by your credit card/debit card company. 

You have 30 calendar days to return an item from the date you received it. To be eligible for a return, your item must be unused and in the same condition in which you received it. Your item must be in the original packaging. Your item must have the receipt or proof of purchase.

PLEASE NOTE:  The purchaser shall be responsible for paying return shipping costs. Initial shipping fees are nonrefundable.  If your return qualifies for a refund you will receive the refund for that item(s) minus a 10% restocking fee.

Customer Reviews

Based on 5 reviews
Well built product

I haven't had a real chance to use this item in the field as of yet, but from initial assessments it appears to be a really good product. The canvas is thick enough and the stitching is well done. I believe that this will be a great pre-filter item for lake and stream water prior to using tablets or boiling. The manufacturers videos (and other reviews) shows how effective and straight forward this item is. To me, if your going to use water from lake or stream sources taking this extra step is important and it's a no-brainer use item! I bought the personal use size and am very pleased with it.

jason jepsen

works very well and compact

Brian Starr
The Brown Filter Bag

I love the group size. I have 3 already and will acquire a few more. I will have at least three for my family (at any one time) and maybe 3 more for “Just in Case” scenarios or bartering purposes. I also have an abundance of water treatment options ALWAYS on hand with an abundance of bartering ability on hand. Chance favors the Prepared Mind!

j dodd

The Brown Filter Bag

Donald Bercot
Finally Got One!

I've been wanting one of these for a long time and I'm very happy with the quality and especially the service! Thanks to the crew over at Survival Gear BSO for getting this out to me so fast.

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