Originating from South Asia to Australia, Casuarina Cones have similar benefits as alder cones but with a very unique visual appeal. Casuarina Cones make the perfect hiding spots for shrimplets, with the development of biofilm on the many surfaces serving as food for their early days. Slightly more durable then alder cones, Casuarina Cones help to create a more natural look and make a great addition to any tank. To reduce the tannin affect and help to sink faster you can boil them first.