Pond Filtration Options: Which Do You Need?

Pond Filtration

September 10th, 2017   |   Updated on July 18th, 2018

While filters aren’t necessary in every pond, they are if you desire clear water in your pond, have a deep or large pond, or have lots of fish and thus an over accumulation of ammonia. Filters remove unwanted particulate from your pond, such as biological waste.


There are several options for pond filtration and we’ll walk you through them all so you’re sure you’re getting the right system for your pond.

Chemical Filtration

Chemical filtration is not as common in ponds as it is in aquariums, but it is still used occasionally, mostly in combination with some other system of pond filters. This filtration system uses chemicals like resins, carbons, and the like to attract pollutants in the pond and pull them out. This type of filtration can help balance out your ammonia levels, as well, which can increase due to having a lot of fish or decaying organic material, such as plants.


Physical and Mechanical Filtration

Physical and Mechanical Filtration

Mechanical filters help prevent clogging in the pond as well as prevent sediment from collecting on the bottom, all while making the appearance of the water clearer. They skim and strain unwanted debris like leaves and floating algae from the surface of the pond’s water. These systems require weekly cleaning and sometimes, more frequent cleanings than that.

Biological Filtration

Biological Filtration

This filtration system is crucial for ponds with a lot of fish or decaying plants causing them to have too much ammonia in the water. Biological filtration systems reduce the amount of ammonia in the water by using a nitrogen cycle to detoxify the waste products in the water. This cycle takes four to six weeks to complete and, though there are products on the market that claim to speed up the process, but nothing replaces the quality of the effect of letting the cycle run its natural course for the full duration of time.

This filtration option may not be necessary in ponds without liners, due to the properties of the soil that’s acting as a liner. This should be done to all new ponds with liners and aquariums before you add the fish, because the chemical imbalance could kill them.

Not every pond requires a filtration system, but if you’re wanting the water in your pond to appear clearer or you have a large pond with a lot of fish, this might be the best option for you. Ultimately, the decision of which filtration system to go with should depend on the type of pond, the reason for the filter, how many fish you have if any, and how much money you have to invest on this.