A water filter is a device that purifies water. A water filter consists of a large plastic bottle, a piece of cotton wool, stones, sand and a piece of filter paper such as coffee filter or blotting paper.
To assemble the water filter the plastic bottle is cut in half. The top half is placed upside down in the bottom half like a funnel. The cotton wool is placed in the neck of the bottle. The cotton wool is covered with a layer of stones, followed by a layer of sand. Finally the filter paper is placed on top.
When dirty water is poured carefully over the filter paper it will drip down slowly into the bottle below. This water is noticeably clearer.
More sophisticated water filters are used in the Waterworks. They also use chemicals to kill harmful bacteria in the water.
To assemble the water filter the plastic bottle is cut in half. The top half is placed upside down in the bottom half like a funnel. The cotton wool is placed in the neck of the bottle. The cotton wool is covered with a layer of stones, followed by a layer of sand. Finally the filter paper is placed on top.
When dirty water is poured carefully over the filter paper it will drip down slowly into the bottle below. This water is noticeably clearer.
More sophisticated water filters are used in the Waterworks. They also use chemicals to kill harmful bacteria in the water.
