Java fern
Microsorum pteropus
Water parameters
Light and nutrients
Substrate type: epiphyte. Propagation: rhizome division.
Substrate compatibility
| Substrate | pH effect | Nutrient load |
|---|---|---|
| Wood and rock mounts (Hardscape mount) | varies | none |
| Inert sand (Pool filter sand) | neutral / inert | none |
| Inert gravel (Aquarium gravel) | neutral / inert | none |
| Limestone gravel (Crushed coral) | raises pH | none |
| Bare bottom (no substrate) (Bare bottom) | n/a | none |
| Aquasoil (ADA Amazonia) | lowers pH | very high |
| Mineralized clay substrate (Seachem Fluorite) | neutral / inert | moderate |
With fish
Origin and habitat
Native to tropical Southeast Asia (Thailand, Malaysia, Indonesia, Philippines, southern China), growing attached to rocks and wood in and alongside streams and rivers. The species (Microsorum pteropus) is one of the most widely recognized aquarium plants in the world. The leathery, dark green fronds grow from a creeping rhizome and reach 15–30 cm tall in the standard form. Several cultivars and variants are commercially available: 'Narrow Leaf' (long, thin fronds), 'Windelov' (forked, lacy tips), 'Trident' (narrow fronds with finger-like projections), 'Philippine' (wider, hammered-texture fronds), and various miniature forms. Java fern is a staple of low-tech aquariums because it tolerates low light, no CO2, and a wide range of water conditions. The tough leaves are unpalatable to most herbivorous fish.
Outdoor pond use
- USDA zones
- 8–13 (winter low around -12°C or warmer)
Care notes
Among the easiest aquarium plants. Attach the rhizome to driftwood or rocks using super glue, thread, or fishing line. Do not bury the rhizome in substrate; like Anubias, burial causes rot and death. The roots anchor the plant to hardscape surfaces over time. Low to moderate light is ideal. Under high light without CO2, the slow-growing leaves attract algae (especially black beard algae and green spot algae). Growth is slow to moderate: one new frond every 1-2 weeks per growth point. CO2 is not required and makes relatively little difference to growth speed compared to its effect on stem plants. Tolerates pH 5.5-8.0, soft to hard water, temperature 20–28°C. Propagation is by rhizome division and by adventitious plantlets that form on mature leaves (small plantlets sprout directly from the frond surface, eventually developing their own roots and falling off). The plantlets can be collected and attached to new locations. Brown or black spots on leaves are either spore patches (normal reproductive structures, not disease) or early stages of plantlet formation. Trim old, damaged, or heavily algae-covered fronds at the base. Java fern's combination of durability, aesthetic versatility, and fish-resistance makes it the default recommendation for beginners.