Java Fern / Microsorum

Java fern (Microsorum pteropus) is an epiphyte — tie or glue its rhizome to aquarium wood or rock with the rhizome sitting on top of the surface, never buried in the substrate. A buried rhizome rots and the plant melts. Cotton thread, fishing line or a dab of gel superglue all work; within a few weeks the roots grip the wood on their own.

No. Java fern is a hardy low-tech plant that grows in low to moderate light with no CO2, which makes it ideal for beginner and community tanks. It grows slowly, so keep lighting modest — intense light without CO2 tends to grow algae on the leaves rather than speed the plant up.

Those are baby ferns — Java fern propagates by growing plantlets on the undersides and tips of mature leaves. Once a plantlet has a few small leaves and roots of its own, gently detach it and attach it to new wood or rock, where it will grow into a full plant. It is the easiest way to spread Java fern through a tank.

Small black spots and lines on the underside are usually spores or new plantlets — normal. Widespread browning is most often too much light, or a buried rhizome starting to rot. Move the plant to shadier flow, make sure the rhizome is exposed, trim badly affected leaves, and healthy new growth will follow.