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His filter has basically two stages: A series of mechanical filters (coarse rocks, fine rocks, coarse sand, fine sand) to remove macroscopic contaminants (eg. dirt) from the water. By using seve...
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His filter has basically two stages: A series of mechanical filters (coarse rocks, fine rocks, coarse sand, fine sand) to remove macroscopic contaminants (eg. dirt) from the water. By using seve...