The Best Koi Pond Filter Media - How to Pick the Right Kind

Just like filter systems themselves, there are many choices when it comes to the various types of filter media. The most common questions I hear asked are "what type of filter media is best " and "what is the best combination of media to use."

First, all media perform either mechanical or biological filtration - or both. You need both kinds in your Koi pond so what are they. Mechanical filtration is trapping solid wastes and removing them from the water. Biological filtration supports the growth of beneficial bacteria that break down pollutants in the water.

Japanese matting has become one of the most popular and widely used for biological filtering. It is made from thousands of fiber strands formed into a sheet or mat. Do not use this medium for mechanical filtration since it will easily clog and require repeated cleanings that will eventually lead to disintegration. Another good type of biological filter medium is bacballs. They are easy to work with and clean. Again, don't use them in the early stages of the filter system as they too may become clogged and require cleaning often. Bioflow and flocor are plastic pieces that are light weight and easy to clean and good for biological filtering. Aquarock is another good media for biological filters.

If you don't have a vortex chamber as your first stage of filtration, you will want to use brushes in the first stage to trap the large solid waste material. Brushes are easy to work with and clean. You can be sure they will need frequent cleaning depending on the waste load of your Koi pond.

So what is a good setup? Well the answer might be different depending on who you ask but here are some suggestions. If you have a pump-fed multi-chamber system without a vortex you would want to consider having brushes in chamber one, followed by flocor or bioflow in stage two, followed by Japanese matting in stage three. If you have additional chambers consider adding matting, foam or Aquarock.

If you have a gravity-fed system with a vortex chamber, it could use a similar setup except the brushes would not be needed. Alternatively, with a vortex as the first stage, I like to use some form of matting or matting and foam in all the chambers after the vortex. Whatever your setup, do a little homework before you select the best setup for your Koi pond.