Building a mechanical/biological filter for your pond is an easy project which can be completed in under an hour, in most cases. Assuming you already have a drill, parts for this project can be obtained for less than £19.
- Skill level:
- Moderately Easy
Things you need
- 1-inch hole saw
- Plastic container with watertight lid
- 1-inch PVC through fittings (2)
- 100-percent silicone aquarium sealant
- Filter sponges (2)
- Plastic practice golf balls
- Filter pad
Drill two holes in the plastic container using the 1-inch hole saw. One hole should be through the lid, close to centre. The second should be through the side, near the bottom of the container.
Secure the PVC fittings into the holes you just drilled. Seal them using the silicone sealant. Your hoses for water flowing to and from the pond will attach to these fittings.
Insert a filter sponge halfway into each of the two fittings. These are the first and last stages of mechanical filtration.
Fill the container nearly to the top with the plastic golf balls. These will serve as a breeding ground for bacteria which provide biological filtration. Leave only enough room at the top for a layer of filter pad.
Cut the filter pad to the size of your container, and lay it over the top of the golf balls. This provides your second-stage mechanical filtration.
Close and seal the lid of the container and attach your input hose to the fitting on the top and your output hose to the fitting on the side.
Tips and warnings
- Plastic golf balls with holes in them work best, as they provide more surface area for the beneficial bacteria.
- Always utilise proper safety equipment when working with power tools.