Gravity or pump-fed pond systems

When planning or having a new pond built, it's important to carefully consider the options available. Is sustainability important? Do you want to save money? Do you prefer ease of use? Do you want a natural-looking pond or a sleek tank? In short, there are quite a few choices to be made. A well-known saying in the koi hobby is that the third pond built is the first good one. Making a good plan before you break ground can save you a lot of money and effort.

What is a pump-fed pond system?

With a pump-fed filter, the filter system is positioned above the pond's water level. The pump is located in the pond and pushes the water toward the filter. After passing through the filter system, the water flows back into the pond naturally.

What is a gravity fed pond system?

With this option, you bury the filter next to the pond. An open pipe connecting the pond to the filter ensures that the water level in the pond is equal to the water level in the filter (law of communicating vessels). The pump runs after the filter and pumps the water into the pond. This raises the water level in the pond, but simultaneously, due to the law of communicating vessels, the water pumped out of the filter is replenished.

What do I choose?

Below, I'll outline the pros and cons of both systems. This will help you make a better choice.

Advantages of Gravity compared to Pump-fed

Lower energy consumption. The pump doesn't have to lift the water as high.
Cleaner water:

Because the water is pumped behind the filter, the coarse dirt is not ground finely by the impeller in the pump, as is the case with a pump-fed system.
Because a bottom drain is usually used to keep the bottom clean.

Reduced pump maintenance. The pump doesn't move water with large particles of dirt and therefore doesn't clog up easily.
More space in the garden. Because the filter system is buried, you can create a patio by the pond, for example.
Aesthetically more appealing. There's no major obstacle (filter system) in the garden.
Less chance of damage to the fish because there is no pump (with potentially sharp parts such as hose clamps) in the pond and the fish cannot be sucked in.