Singapore Zoo is covering an area of 28.3 hectares. Natural scene in the park instead of fences, creating a natural living environment for all kinds of animals. There are about 3000 animals running free and living peacefully with tourists. It has been installed more than 40 nos POOLKING's stacking horizontal sand filters in Sea Lion ,Manatee ， Penguin hall . POOLING is the first manufacturer in China to produce stacked horizontal sand filter.