!: Pump-Fed Or Gravity-Fed Koi Pond - Make the Right Choice

There are two choices when it comes to the basic construction of your koi pond filtration system. You can use either a pump-fed or gravity-fed system. There are advantages and disadvantages to both so you need to carefully consider the alternatives.

In the pump-fed koi pond, dirty water from the pond is pumped from the koi pond to an external filter and clean water is return to the pond by gravity. A pump-fed pond requires two design components. There has to be a pump in the pond and the water has to be pumped to a higher level than the pond to allow for a gravity return. There are two main disadvantages with this type of design. The pump is in the pond pumping dirty water making it more susceptible to frequent clogging requiring maintenance. It also has to be powerful enough to lift the water to the filter system. This external filter system sitting higher than the koi pond can make hiding it with landscaping more difficult. However, an advantage of this arrangement is that a water feature such as a waterfall can be constructed to act as a water return.

These systems are the easiest to install and are relatively inexpensive. Since you will never be able to pump all the waste from the bottom of the pond, you will need to vacuum the pond to do this effectively. Ease of construction and installation is a definite trade-off with expense of maintenance of the system.

In a gravity-fed system the water in the koi pond and the filter system are at the same level. A pump is placed in the last chamber of the filter system to pump clean water back into the pond. A drain in the floor of the pond is used to drain dirty water into the filter system by gravity. Unlike the pump-fed system the pump in the gravity-fed system is pumping clean water and less likely to get clogged. Maintenance costs will be less with this type of filter system. Because the filter is at the same level as the pond it can be more easily accessed for maintenance and removal and can be easily hidden by wooden deck work and landscaping.

All in all the gravity-fed system is a better long term choice than the pump-fed system even if it is a little more expensive to initially install.