Collection: Pond Filters

A professional pond filter is the engine of your water feature's health. Beyond basic cleaning, it maintains the biological balance needed for fish vitality and water clarity. Without effective filtration, organic waste accumulates quickly. This leads to toxic ammonia spikes and uncontrolled algae growth.

Our systems are built for various climates. They ensure biological stability from freezing winters to intense summer heat. Explore our high-capacity pond filters to create a safe, crystal-clear environment for your aquatic life.

Three Stages of Pure Water

Effective pond filters mimic natural self-cleaning processes. Most professional units combine three treatment methods:

1. Mechanical Cleaning

This stage traps visible debris like silt, leaves, and fish waste. It prevents clogging of the biological media and keeps the water visually clear.

2. Biological Conversion

The heart of the system. Colonies of beneficial bacteria convert toxic ammonia into safe nitrates. This maintains the essential nitrogen cycle for your Koi and goldfish.

3. UV-C Clarification (Optional)

UV light destroys single-celled algae to stop "green water." Important: UV-C manages clarity and pathogens, but it does not replace the biological filter—it works alongside it.

Pump Compatibility & Installation

These gravity-style filters work seamlessly with solids-handling pond pumps and waterfall pumps. Since water leaves these units via gravity, the filter must be placed at the highest point of your waterfall or stream. For systems where the filter must be hidden at ground level, see our Pressure Filters.

System Application Guide

Match your filtration capacity to your specific pond type:

Water Gardens: Focused on algae control and clarity for plants and lilies.
Koi Ponds: Requires massive bio-media volume to process waste from heavy fish loads.
Streams & Cascades: Ensures the water remains debris-free as it flows over rock ledges.

Frequently Asked Questions About Pond Filters & UV Clarifiers

How do I choose the right filter size?

The filter should process the pond's total volume every 1.5 to 2 hours. If you have fish (especially Koi), double the rated capacity to handle the higher organic waste.

Can I use any pump with these filters?

Yes, they are compatible with most pond and waterfall pumps. Ensure the pump's GPH does not exceed the filter's maximum intake rating to prevent overflowing.

Does a UV clarifier replace a biological filter?

No. A UV clarifier only kills suspended algae and some pathogens. You still need mechanical and biological media to remove physical debris and process toxic ammonia.

How do I winterize my filter in cold climates?

In Canada and the Northern US, drain the filter completely to prevent ice damage. Clean the media and store sensitive parts like UV bulbs and quartz sleeves in a frost-free area.