Water storage - filtration - purification is where a lot of people seem to be lacking in their disaster prepardness plans. This is where something like a Berkey water filter can come into play.
The Berkey water filter in this video was supplied by Red Barn Workshop - who has a wide selection of hiking, camping and disaster preparedness supplies.
Each filter has an estimated life of around 3,000 gallons. With 2 filters, the Berkey Light has an estimated life of around 6,000 gallons. Either way - 3,000 or 6,000 gallons, that is a lot of water.
