There are several options when it comes to choosing a koi pond filtration system. While the options are varied in placement, cost, and level of maintenance, they all work in the same basic way to circulate the water in the pond to keep the algae level down and the water healthy for your ornamental koi. The three basic types of koi pond filter options are skimmer and waterfall, submersible, and external.
In addition to filtration systems, plants also bring essential oxygen as well as add to the visual appeal of your pond. Before making any decisions, it is important to know what you are looking for in a system based on cost, level of maintenance, space required, and visual appeal.
A skimmer and waterfall system consists of an external pump and a waterfall return. It works by skimming leaves and other trash from the surface of the water, collecting it in a waste basket, and pumping the filtered water to the waterfall. This type of system offers simple maintenance and well-concealed equipment and is best suited for medium to large ponds. There is a moderate amount of landscaping and plumbing that would be required in order to hide the equipment and to make the waterfall. A system like this would cost between $450-$1200 depending on the materials used and what is already on hand.
Another option to consider would be a submersible filtration system. If you have a small pond with few fish and are looking to keep things simple, this might be the system for you. The filter sits on the bottom of the koi pond and suction draws in water and debris and filtered water is sent to fountain to gain oxygen. Cleaning the filter requires more maintenance than skimmer, but everything is hidden underwater and there is no landscaping needed. This system can be set up for as little as $80-$300.
A third option available is external filtration. This type of filtration requires landscaping to hide the unit and but access is simple and maintenance is minimal. The filter draws water to the external unit and then uses a waterfall or stream for aeration. This option offers the most freedom with placement and configuration and is great for either small or large ponds. The cost is flexible as well and complete setup will run $90-$2150 depending on how ornate you wish the pond to be. The best thing about this option is that you can make a pond simple or very elaborate.
Now that you know the options available for filtering your koi pond, it is best to make a list of the pros and cons for each filtration option. In the interest of time and money, it is best to be sure of your unique needs so that you will not have to redo the koi pond filtration system.
As long as you know your size, price, and ornamental needs ahead of time, you should be well prepared to choose a koi pond filtration system with confidence.