6 Reasons Why Java Fern Is Melting (And 4 Easy Fixes)

The first few things that pop up when talking about Java Fern is that it looks great, simple, and easy to maintain.

However, my experience with growing Java Fern tells another story.

When I bought my Java Fern from a local aquarist, all the leaves eventually browned within a week and became translucent. It was a nasty mess. I removed the rotten leaves as soon as I saw them, but the plant still did not grow back to normal.

After a while, I got another rhizome from the aquarist. Nonetheless, it was a mess again.

If you are experiencing the same, I can help you. My experience with Java Fern has made me research it thoroughly.

The most common reasons for Java Fern melting are excessive lighting, insufficient nutrients in water, incorrect planting, and too much algae in the tank.

This article will tell you what caused my Java Fern to melt and how to avoid it. I will also discuss how to prevent brown spots and some tips for caring for the Java Fern so that it does not die prematurely.

Reasons Why Java Fern Has Brown or Black Spots

Java ferns can often die or melt, especially after they’ve been bought. But soon, they will spring back as new. Java Ferns requires time to adjust to a new environment.

Here are some reasons why Java Fern has black or brown spots:

1. Your Java Fern Is Under Excessive Lighting

Java Ferns are tropical plants that lie low on the base of tropical rainforests’ floor, usually in flooded areas. That’s why they can be partially or completely submerged in water without too much risk.

If you have placed a Fern in an unshaded region, it is probably turning brown since it is not its natural dark environment.

2. Your Java Fern Isn’t Properly Planted

Improper planting may be another reason for you seeing brown spots on the Fern.

Ferns are a type of aquatic plant that most novice aquarists can’t seem to keep alive. Java Ferns lack roots and anchor themselves using rhizomes. They also need to be planted with their rhizomes in the substrate and will not grow when planted on top of rocks or gravel.

3. Your Java Fern Is Still Adjusting To A New Environment

As said earlier, if you have recently purchased Java Fern, wait until your Fern has adjusted to the new environment. They may turn brown and mushy, but after a while, they will spring back fresh.

You can cut out the rotten part. However, if the problem persists, try mimicking Java Fern’s natural habitat.

Once the plant settles in, it really is one of the easiest plants to maintain.

4. There’s Too Much Algae in Your Tank

Although Java Fern is generally not affected by diseases or bacteria due to algae, the only thing that will cause some problems is blue-green algae or cyanobacteria. They aren’t attacking your plants, they’re competing for key nutrients. That leaves little nutrients to go around for your Java Fern.

5. Your Aquarium Lacks Nutrients

Java ferns usually get nutrients from the water, but they may start to develop “spots” (little brown/black dots) if they don’t get enough nutrients. To stop the process from getting out of hand, try to encourage a healthy growth of plantlets and rhizome anchoring. You can also add nutrient additives, but do some research before adding.

6. Your Java Fern May Be Propagating

Seeing brown/dark spots does not necessarily imply that your Java Fern is dying or has some disease. 

It may be because your plant is propagating. Java Ferns reproduce through apomixis. Ferns are able to reproduce by “cloning.” If you notice small black spots on the underside of their leaves, it means that they are flowering.

java fern melt

How To Prevent Black Or Brown Spots On My Java Fern?

Here are some tips to prevent brown or black spots:

  1. I don’t recommend fertilizing these plants very often. They take in all the nutrients they need from their water. If you do fertilize them, it will promote natural growth and stop them drying out. If you feel it is needed, just give them a quick dose of liquid fertilizer once in awhile
  2. Novice aquarists think that all aquatic plants need to be planted on the substrate. This is a common mistake that might lead to Java Fern turning brown. 
  3. Let the Java Fern adapt to your aquarium environment.
  4. Keep it in a shaded area and prevent direct light from falling on it.
  5. If your tank is getting too much algae, make sure to take some of it off.

How To Recover A Java Fern That Has Spots?

Usually, small brown spots are not something to worry about because they may be simply reproducing. But if your Fern has large brown spots and it has become mushy, try out the following tips:

  1. Reduce excessive lighting. Keep your plant in the shade and see if their condition improves.
  2. Trim the browning leaves till the rhizome. The plant will gradually adapt to its environment and start putting out fresh leaves.
  3. Start dosing it off with liquid fertilizers once a week. Your plant may be nutrient deficient.
  4. Replace 10% to 30% of the aquarium water every two weeks. This avoids the accumulation of fish waste and nutrients. Dirty water will damage not only Java Ferns but also other plants and fish.

Wrapping Up

After two unsuccessful attempts of replacing Java Fern, I finally managed to grow Ferns without the leaves melting. Adding liquid fertilizers and increasing water changes worked for me. I also realized that I was using CO2 in my tanks which is not a requirement.

In the end, follow the above tips so that your Fern remains healthy and thriving.

I hope you can learn from my mistakes and experience!