In the Indian Subcontinent, "khus" (vetiver roots) is often used to replace the straw or wood shaving pads in evaporative coolers. When cool water runs for months over wood shavings in evaporative cooler padding, they tend to accumulate algae, bacteria and other microorganisms. This causes the cooler to emit a fishy or seaweed smell. Vetiver root padding counteracts this odor. A cheaper alternative is to add vetiver cooler perfume or even pure "khus" attar to the tank. Another advantage is that vetiver padding does not catch fire as easily as dry wood shavings.