Why this? Tips on keeping Java Fern and Anubias

Above: Java Fern 'melt' ( courtesy of Tiffany P.)

Java Fern (microsorum pteropus) and Anubias barteri ‘nana’ are among the hobby’s most hardy plants.
They can thrive in both softwater and hardwater, and can take anything from high to very low amounts of light. They don’t need CO2 or substrate to grow well. Their tougher leaves make them less vulnerable to herbivore damage, and less susceptible to handling damage during transport and planting.

However, their external toughness belies several weaknesses.

When overlooked, it is easy to get leaves that covered with brown algae and/or blackened edges. These two species are also prone to displaying ‘sudden death’…where a plant that seems OK might suddenly turn yellow, transparent or even ‘melt’ away.

Above: a common occurrence on the leaves of Anubias (courtesy of Tiffany P.) As slow growers, both Java Fern and Anubias are especially vulnerable to the following:

1. Fish waste. As slow-growing plants, Java fern and Anubias are more susceptible to algae than faster-growing plants. With an undersized filter and infrequent housekeeping, detritus accumulates on their leaves. This feeds the algae and often results in an unsightly brown/black layer.

2. Insufficient flow. Many tanks use overhanging or 'hang-on-back' filters. These filters are more prone to clogging by design and many do not provide sufficient flow. Without sufficient water movement, detritus accumulates on the leaves. This provides a food source for algae.

3. Insufficient light. As shade plants, Java Fern and Anubias can survive in very low light. However, in a tank with floaters (see our previous article here) or taller plants / hardscape, it is easy to go below the minimum threshold without knowing it. If you notice very few or no new leaves, you may be giving too little light.

Sudden death?

Above: a ‘low tech’ tank with a lively fish population and thriving Java Fern and Anubias plants. This tank requires very infrequent cleaning ( water change once every 2 weeks, glass that remains clear of algae) The secret? A large part comes from good flow, in this case a properly sized canister filter.

Regardless of your present equipment or tank setup, 3 things you can do:

1. Regularly change water The 2Hr Way. Stir up and siphon away the detritus on the leaves.
2. If you already have algae covered leaves, review lighting and remove the ones that are too badly decayed. APT FIX is an effective algae treatment for leaves that are still fundamentally healthy.
3. If you are using a hang-on back, clean it more often to help with flow.

Finally, remember the delayed 'cause and effect' in these slow growers. Don't expect improvements to show up immediately. It takes several weeks. And 'looking OK' may not mean 'healthy' or 'happy'. Always look for new leaves.

For more details, read our guide to Java Fern here and our article on keeping Anubias here.