If you are thinking about building a water garden, don’t forget to think about the necessity of filtration! If you plan to include a water pump to recirculate the water, filtration is essential! This will help your pond stay beautiful and healthy for many years.
What is Water Filtration & Do I Need it?
Water Filtration is essential for the quality, health, and beauty of your water garden. While it may look like you’ve created a natural setting, the truth is that it is still a closed system and will need some help to maintain its functionality. Water filtration is a process of removing excess nutrients, debris, and other undesirable things from your water to maintain the health and attractiveness of your water garden and its inhabitants.
Main types of filtration:
Surface skimming: This is probably the simplest type of filtration. It involves using a net or modified pool/fish net to keep or scoop debris out of your pond. It usually needs to be augmented by vegetable, biological, or mechanical filtration.
Vegetable filtration: This involves using plants to help take excess nutrients out of the water and prevent algae blooms. This is a wonderful type to use, especially if your pond is not near its biological carrying capacity. Two typical types involve building a stream with growing plants, or having plants growing in the pond itself. A small pond can use vegetable filtration without a water pump if it is lightly stocked with fish.
Mechanical filtration: This involves forcing water though some type of medium (material, usually porous) to catch the algae, leaves and other undesirables. It also helps the water circulation to create a better flow of nutrients and oxygenated water through the pond.
Biofiltration: Using aerobic (oxygen-loving) bacteria to remove sludge and excess nutrients. These need to be in slowly moving water, and have some type of medium to grow on, rocks, gravel or type of
water garden
biofiltration medium.
How to help reduce the need for filtration/less stress on your pump
Don’t have too many goldfish/koi/frogs per square foot of surface area. A general rule is a minimum of one square foot of water-surface per inch of fish-length to maintain health. As your pond nears biological carrying capacity, the need for filtration increases as you keep adding nutrients and organics to the system when you feed the fish, but not all of it is removed by your plants and algae. Another thing to take into account, especially in the fall, is leaves and other debris falling into your pond. Adding a net at or slightly above the surface to catch a majority of the leaves is helpful. Keeping excess debris out also helps maintain high levels of sunlight and oxygen reaching your fish and plants which help keep them healthy.