MAINTENANCE FREE POND FILTER SYSTEM
  Rock and gravel is a very old type of filtration media   Rock and gravel were used for a long time but have   lost favor with many Pond owners. One of the reasons for that fall off Is that the surface area per cubic foot Is Not Very High Or so people think isn’t very high, Yes rock  is a solid material that takes up a lot of space, But that is also a natural material that is formed on a very fine structure. That is in rotated on a microscopic level, The surface  would have a fairly High microscopic surface area Which is never talked about when it comes to talking about gravel  surface areas. A filter using rock  or  gravel  will require a larger footprint  to handle the same size pond as some of  today's newer media, rather it's smaller, the filter the more  frequently it requires maintenance Rocks on the bottom:  When we talked about putting rock and stone on  the bottom of the Pod with meet at least or up a passionate feeling in...