Plant filter

Whether you have a swimming pond, a koi pond, or a natural pond, a plant filter ensures clear water with minimal maintenance and brings more life to the pond and its surroundings. Choose from three ready-made options or build your own self-regulating plant filter.

Marsh filter
Plant filter tower
Floating plant filter
All marsh plants
Step one
Bacta clear

3 natural filtration methods, ranked from best to simplest

How to Make a Wetland Filter

Marsh filter

A wetland area along the edge of the pond featuring STEP ONE and water-purifying wetland plants. Water flows slowly through the substrate and the roots, breaking down waste and eliminating algae. Suitable for virtually any pond and completely maintenance-free.

Plant filter tower

Biofilter

A vertical tower made of crates filled with STEP ONE and hardy marsh plants. Ideal for deep ponds and fish ponds where plants cannot grow on the bottom. Water flows through the tower and is biologically purified. More effective than a floating plant filter.

Floating plant filter

Filter Island

A compact floating island with water-purifying plants. The roots hang freely in the water and filter out nutrients that cause algae growth. Suitable for deep ponds or ponds with fish that eat plants. It also serves as a safe hiding place for fish.

The secret to a natural pond lies in the combination of tall filter plants and short oxygenating plants. This is how nature has worked for millions of years.

Simon van der Velde

Pond specialist and aquatic plant grower

3 essentials for a maintenance-free plant filter

Pond substrate

Filter media

Pond substrate plants Pond substrate a firm footing and allows roots to grow strong. Lava is often recommended but lacks the proper porosity, which hinders root development. And it is precisely those roots that keep your water clear because they absorb nutrients from the water. STEP ONE therefore the best foundation for any planted filter.

Pond edge trim for plant filter

Water-purifying plants

Combine tall marsh plants with low-growing oxygenating plants for the best results. The tall varieties filter nutrients from the water and create a sense of calm, while the low-growing oxygenating plants block sunlight from reaching the shore and directly compete with algae. This provides both natural filtration and protection in a single system.

Pond bacteria

Filter bacteria

The right bacteria ensure clear water without any hassle. They break down Fish food, leaves, and sludge, and keep floating algae under control. That’s why we BACTA CLEAR . A powerful blend of bacterial strains that works in any pond and keeps your plant filter stable. Safe, natural, and easy to use.

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Frequently Asked Questions About a Plant Filter

Pond Advice

Iris yellow
One of the most effective nitrate removers. The plant extracts a lot of nutrients from the water, thereby keeping algae in check. It blooms with striking yellow flowers in May and June and works best when planted in groups.

Acorus
Known as an excellent phosphate remover. Less phosphate means less algae growth. Acorus effectively in a plant filter but also performs well in a standard pond basket.

Mentha
Vigorous grower, absorbs a lot of nutrients, and gives off a fresh mint scent. You can even use it to make tea or tzatziki. The scent helps keep mosquitoes at bay. Ideal as a supporting plant in a plant filter.

Myriophyllum
A robust, low-growing oxygenating plant. It absorbs a lot of nutrients and competes directly with algae. It remains compact and stabilizes water quality, making the plant filter work even better.

Ideally, set aside 1/3 to 2/3 of the pond’s surface area for a plant filter. A total depth of 30 cm works best. Use 20 cm Pond substrate in this area Pond substrate the roots have enough space and the filter can purify the water as effectively as possible. About 10 cm of water remains above the substrate. Because the filter area is smaller than the rest of the pond, extra substrate is needed here to ensure proper functioning.

A well-designed plant filter requires very little maintenance. With Pond substrate good Pond substrate (STEP ONE), the right plants in sufficient quantities, and regular additions of Pond bacteria BACTA CLEAR), the system will naturally remain stable. Pruning is not required. If you do wish to perform maintenance, simply remove the dead flowers in the fall. The actual pruning should be done in the spring. In the fall, leave the leaves on the plant, as they protect it.