from the blog

Choosing the Right Filter for your Outdoor Pond

Care and maintenance

Tips and setup

September 28, 2020

Filtration is one of the most important factors in determining whether your pond will be able to provide a healthy, balanced ecosystem for your fish. Not only do pond filters facilitate water flow which helps to reduce the growth of algae, but they also remove harmful toxins from the water and filter out waste to keep the pond water clear. Adequate filtration is particularly important in ponds where goldfish or koi are present because these fish produce a large amount of waste and require highly-oxygenated water. In order to ensure that your pond fish remain healthy, do some research before selecting a pond filter so you can be sure to purchase the type that is best for your particular pond.

Types of Pond Filter

Before you can begin to peruse your options in pond filters you need to decide between the two major types: external and submersed filters. External pond filters can be very large and are not installed directly in the pond. Because this type of filter is not housed within the pond itself it is much easier to clean and to change or add filter media when needed. Though external pond filters have the capacity to support larger biological loads than submersed filters, they can be unsightly and difficult to disguise.

Submersed pond filters are those which can be installed inside the pond itself. This feature allows you to easily conceal the filter from view using an arrangement of aquatic plants or decorative stones. A submersed pond filter can be filled with different types of filter media, as can an external filter, but this type is more difficult to clean because it must be removed from the pond first. Although submersed pond filters are limited in their ability to support large biological loads, they are extremely versatile and can be used for water features as well as basic pond filtration.

Tips for Selecting a Filter

After you have made your choice between an external and a submersed pond filter you need to select the right model for your particular pond. One of the most important factors in determining which filter is right for you is the size of your pond. Different filters are designed to support different biological loads. The model you choose should be able to filter one half of the total pond volume in an hour. If your pond is located in an area that receives a great deal of sunlight you may need a larger filter to counteract an increased rate of algae growth.

In addition to the size of your pond, the type of filtration you desire should also be a factor when making your decision. Mechanical filtration is the most basic function of a filter which involves removing solid waste from the water as it is drawn up through the filter media. Chemical filtration serves to remove toxins from the water and biological filtration involves maintaining a colony of beneficial bacteria which help to break down wastes and clarify the water.

Regardless of what type of filter you choose there are a few simple things you can do to keep your pond water clean and clear. Avoid overfeeding your fish and take steps to prevent your pond from becoming too crowded. You may also consider adding an EcoBio-Block Wave or EcoBio-Block nsM to your pond in order to facilitate the growth of a colony of nitrifying bacteria. EcoBio-Blocks are made from natural zeolite and infused with beneficial bacteria which will quickly multiply after being introduced into your pond. The presence of these bacteria will speed up the nitrogen cycle in your pond which will result in cleaner, clearer water and a healthier environment in which your fish can thrive.