About the species

Microsorum pteropus, the Java fern, is an Asian water fern and one of the very hardiest plants in the hobby. It grows 15–30 centimetres tall, has leathery, slightly wavy leaves on a creeping rhizome, and belongs on wood and stone rather than in the substrate. The black spots beneath the leaves are sporangia, not a sign of disease as many believe.

Facts

• Latin name: Microsorum pteropus
• Plant type: Rhizome plant
• Origin: Asia
• Height: 15–30 cm
• Growth rate: Slow
• Position: Wood and stone

Light requirement

Low light requirement. It manages with the lighting that comes with most aquariums and is happy in partial shade behind or beneath taller plants. Strong lighting does not harm it, but raises the risk of algae on the leaves because the plant cannot use all the available light.

CO₂ & nutrition

Manages entirely without added CO₂, which makes it as suitable for a simple aquarium as for an aquascape. Liquid carbon or injected CO₂ speeds up growth but is never a requirement. Dose an all-round fertiliser with iron and micronutrients every week.

Planting

The rhizome must never go into the substrate — it will rot. Instead tie or glue the plant onto a piece of wood or a stone using fishing line, thread or plant glue, and leave it until the roots have taken hold on their own. It can also simply be wedged into a crevice in the hardscape.

Rinse the stone in aquarium water and set it in place. It can be moved freely whenever you want to change the layout, and can also be stacked against other hardscape.

Care & propagation

It needs almost no maintenance at all. Propagation is simple: divide the rhizome with sharp scissors or a knife so each piece keeps at least three or four leaves. Make sure there is a gentle current past the plant so no debris collects between the leaves.

Position in the aquarium

It grows on hardscape rather than in the substrate, so it can be placed anywhere in the aquarium — on a piece of wood, a stone or a back wall. That makes it as useful in the foreground as high up in the layout.

Difficulty level

🟢 Easy — grows in most aquariums without CO₂ and under ordinary lighting.

Delivery format

Delivered pre-grown on a lava stone. The porous stone gives the roots an excellent hold and at the same time plenty of room for beneficial bacteria. Placed straight into the aquarium, with no planting.

Recommendation

Along with Anubias, the plant we suggest first to new aquarists and shrimp tanks: it copes with shade, needs no CO₂ and is left alone by herbivorous fish. Small new plants form on the leaves and can be detached and set on the next stone.