The Brown Filter Bag / Mill Bag

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

The Brown 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 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 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 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.

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.