Hepper is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. Learn more.

4 DIY Koi Pond Filters You Can Build Today (With Pictures)

Sarah Psaradelis

By Sarah Psaradelis

koi fishes in the pond

Why spend money on expensive pond filters when you can make your very own DIY filter for your koi pond at home? There are many different DIY plans to choose from when it comes to making your pond filter and most of these methods require affordable items that you might even already have around your home.

If you have an outdoor pond for koi, part of the challenge to maintaining a beautiful pond is keeping the water crystal clear enough to see the koi swimming through the water. Most commercial pond filters are overpriced and require a lot of maintenance, which can take the joy out of keeping a successful koi pond.

With a little bit of patience and lots of creativity, you can create a pond filter for your koi that is the right size for your pond, has a unique appearance, and most importantly, works efficiently to keep your koi pond clean and filtered.

starfish 3 divider

The 4 DIY Koi Pond Filters You Can Build Today:

1. Storage Tub Filter

DIY Fish Pond Filter
Image Credit: The Owner Builder Network
Materials: Large storage tub, foam sheets, plastic piping, pump
Tools: Carving tool, scissors
Difficulty: Beginner

This filter is inexpensive, and the foam sheets can be purchased from your local pet store near the pond section. You may already have a large unused storage tub lying around which will form the basis of the filter and hold the media inside. You’ll need to carve two separate holes at the top of one side to connect the plumbing system so it can be connected to your pond.

This plan offers mechanical and biological filtration, as the foam sheets will trap in dirt and debris that would otherwise cloud your pond, while also providing a large surface area for nitrifying bacteria to grow.

2. Hose Pipe & Tub Filter

Materials: Large storage tub, piping, hose pipe, pump
Tools: Carving tool
Difficulty: Intermediate

This filtration plan is slightly more complicated but very effective at running a good filter system through your pond. You will need to find a good placement to run the hose pipe through the tub to create a flow. Stones can be placed inside the tub to weigh the tub down, and you also can grow plants in the stones to make the filter look more attractive. If you do add plants to the top, they will use the nitrates from the pond water to grow, creating a balanced aquaponic system. The irrigation pipes can be purchased from your local hardware store and bolted into the large tub.

3. Bucket Method

DIY Pond Filter System
Image Credit: WikiHow
Materials: Bucket, lid, pipes
Tools: Carving tool
Difficulty: Beginner

This is a simple DIY pump ideal for beginners. One pipe is connected to the top of the bucket where it will flow inside the bucket and through the filter media you choose to put inside and then filtered back into the pond. This is a good idea for small ponds, and the size of the bucket will depend on the size of your koi pond, so you can be creative with what you choose to put into the bucket and the size and color option you choose.

4. Sponge Pond Filter

DIY Pond Filter
Image Credit: Red Fork Hippie
Materials: Tub, dish sponges, long narrow tube
Tools: Carving tool
Difficulty: Beginner

This is a beginner-friendly DIY koi pond filter for small ponds. The logistics are simple to understand and not much work is required to make this filter work. All you will need is a round tub with a lid, which can be found in your home or purchased from a store, and tubing which will go through a hole carved in the middle of the lid.

The main type of filtration for this system is from the dish sponges which should be filled in the tub. This is a great way to biologically filter your koi pond because the sponges provide a breeding ground for beneficial bacteria.

aquarium plant divider

Final Thoughts

There are so many creative ways to make a DIY koi pond filter! The type of filter you choose should be easy for you to create and install while providing enough filtration for the size of your koi pond. If you are struggling to keep your pond clean because debris and leaves are falling into the pond, then you’ll want to choose a DIY filter that has netting or foam sheets to catch this debris. If you have a small pond, then a small return valve filter may be a good option for you.

Featured Image Credit: NatalieStamer, Pixabay

Related Articles

Further Reading

Vet Articles

Latest Vet Answers

The latest veterinarians' answers to questions from our database