Vortex Filtration, Cyclone filtration, Settling Tanks and Multi Chamber filter systems are our specialty. Laguna Koi Ponds has been installing and using these types of large gravity flow systems for many years.
A gravity flow system consists of large open tanks typically at pond level or above pond level. A gravity flow system has definite advantages over pressurized types. These systems give you the greatest filtration and economy of electrical use. See Filter Comparison Article.
Large gravity flow systems require more attention to detail than smaller type systems. However, once installed correctly you will have a filter that works for you. A large filter gives greater filtration and better pond water quality. They are able to handle much higher fish loads and feeding rates than a smaller pressurized type filter.