Java Moss Guide for Beginners and Experts: Care, Growing Plant Profile

Beginner and advanced aquarists enjoy using Java Moss to create beautiful underwater landscapes.

Since Java Moss grows quickly and readily absorbs nitrates from aquarium water, it also plays an essential role in aquarium health.

Even though Java Moss is easy to care for, it will be to your advantage to know how to get the most from it.

Quick Overview Facts on Java Moss

About Java Moss and How to Use it in an Aquarium

Java Moss is one of several aquatic plants that take nutrients directly from the water as opposed to via roots that must interact with some type of substrate.

Just about any aquarium can benefit from its capacity to improve water quality by removing nitrates from the water. 

Here are some of the most popular ways people use Java Moss in freshwater aquariums:

• Free floating – as a means of providing shade from overhead light sources
• Attached to driftwood and cave surfaces – to create hiding places for fish and other tank inhabitants
• Lightly anchored to substrate – to create grass-like carpets on the bottom of the tank.
  • This works especially well in breeder tanks for egg laying fish, as well as in tanks with shrimp that hide in it, or other creatures that enjoy digging through the Java moss looking for food.
• Along aquarium walls – to eliminate mirror effects generated by external lighting 

Some aquarium keepers claim it is a good idea to plant Java Moss near filters in order to hide them.

Given how quickly this plant can grow, I don’t advise this at all because the Java Moss can easily clog filter inlets. This can spell disaster, especially if the tank is overstocked, overfed, or not properly cycled. 

If you don’t like the sight of a filter, put it behind a piece of driftwood or something else that won’t interfere with its proper operation.

When you put Java Moss near the filter, it will also get additional nutrients because everything in the water will eventually go through the filter.

Without a question, if you don’t have time to keep up with trimming this plant on a monthly or bi-monthly basis, it will be even harder trying to keep new growth away from the filter.

Tank and Tank Mate Requirements

Since Java Moss can be trimmed back until it is just a few inches long, or allowed to grow in huge swatches across any available space, it can be placed in any tank size. It will also grow well in tanks with robust water circulation. 

If the water current is milder, you will need to keep the plant well trimmed so that all parts of the plant get access to nutrient rich water.

The key to healthy Java Moss growth isn’t so much about a rapid current as it is making sure that nutrients flow evenly across the entire plant. I usually like to make sure that all strands of moss are waving just a little bit in the current. 

Insofar as tank mates, Java Moss grows so quickly, many aquarium keepers find themselves wishing they could find fish that would consume it as a matter of habit.

Oddly enough, even some of the most voracious plant eaters leave Java Moss alone.

You can safely use this plant with Goldfish, Buenos Aires Tetras, Cichlids, and any other species that would normally pose a problem to rooted aquarium plants, or ones that have a slower growth rate. 

How to Maintain Java Moss

As with many other aquarium keepers, I have found that the most important part of Java Moss care is keeping it properly trimmed. During the first few months of a new aquarium setup, you may get away with trimming it only once a month. 

By the time you hit the six month mark, Java Moss should be well established in your aquarium. If you haven’t been keeping it trimmed back, you can expect it to take over nearby decorations and spread anywhere it can reach.

At the year mark, you can expect to be trimming this plant back on a bi-weekly basis. The more light and nitrates you have in the fish tank, the faster this plant will grow.

In one sense, Java Moss is almost as bad as algae when it comes to rapid growth. The key difference is Java Moss will not develop into water borne micro blooms that can get into fish gills and pose a threat to them. Java Moss is also easier to trim and manage than algae. 

Trimming Java Moss is a very easy task – you can use aquarium-safe scissors, or simply break chunks off with your fingers.

I usually like to trim mine back to about 1 ½ inches on carpets, and then leave just a bit more on overhangs and driftwood tree arrangements. 

As a new aquarium keeper, you might feel hesitant to trim Java Moss back to such an extent. In this situation, leave a piece or two untrimmed while you test your skills on other pieces. If you make a mistake, propagating Java Moss is very easy. Just break some off from an existing plant and anchor it to the new location. 

How to Make Java Moss Shapes

When it comes to inexpensive, versatile aquarium decorations, Java Moss gets high scores.

Here is how to get the most popular shapes for your tank.

Regardless of the form, all you need is a little bit of Java Moss, some aquarium safe plastic screen or pieces of mesh, and fishing line. The key to each shape is in how you anchor the Java Moss to the structure, and then where you place it in the tank. 

Carpets

There are two ways to make a moss carpet.

First, you can stick cut tips of Java Moss into the substrate and let it fill in the holes between clumps.

Second, you can anchor the Java Moss to a plastic mesh with string and then let the screen rest along the substrate.

I prefer the second method because it is much easier to keep the plant in controllable sections. This becomes very useful, especially if you wind up with excessive algae growth and need to lift large amounts out of the tank for cleaning. 

Moss Trees

You will need a piece of wood that can be used to represent tree trunks and branches.

Next, just anchor some Java moss on sponge bits along the branches so that it looks like groups of leaves.

If you trim the Java Moss Trees often, they will look more compact, like a maple tree. For a weeping willow effect, just let the moss grow a bit more until it hangs over the branches. 

Java Moss Wall

This method is very similar to what you would use to create a carpet, with the exception of using suction cups on the back of the screen to attach it to the wall of the aquarium.

Moss Ball

Some people will tell you to just roll the moss up into a ball and secure it in a few places with string. I find that method virtually useless because it means there will be a huge area in the center of the ball that never receives nutrients. 

You will be better served by getting an aquarium safe spherical form, and then attaching the Java Moss to that using string. This will ensure that every part of the new plant receives proper nutrients. 

Cave Overhangs

Start by attaching plastic screen to the cave structure.

Depending on the material the cave is made from, you may need to spot anchor the screen to the cave with aquarium safe super glue. If this is not possible, then use strips of aquarium safe sponge instead. Usually, it is much easier to glue sponge to other materials than plastic. 

Once the anchor material is attached to the cave, you can go ahead and use string to anchor Java Moss to the cave. If I want a hidden cave, then I simply let the front portion of the Java Moss form an overhang, and then trim the back areas more in line with the underlying structure.

Common Problems with Java Moss

Usually, Java Moss is a very carefree plant that will require very little beyond routine trimming. Fortunately, solving the following problems isn’t especially difficult.

Turning Brown

If the nitrogen cycle in your tank is properly established, there should be plenty of food available for Java Moss.

Sections of it may turn brown, however, if they aren’t getting enough light or nutrients.

You can correct lack of nutrient problems by trimming the plant back so that inner portions get more nutrient rich water flowing over them. 

If you have a fairly deep tank, and the carpet is turning brown, it may not have enough light.

Remove some floating plants that may be blocking light from the hood array, or put lights outside the tank near the bottom.

I do not recommend putting electric lights inside the aquarium, even though there are some that are supposedly safe to put under water. 

Covered in Algae

The easiest way to get rid of algae in Java Moss is to introduce freshwater shrimp, such as Cherry Shrimp, and snails to the tank. They will help keep the algae under control while you address water chemistry and lighting challenges. 

If the infestation is mild to severe, remove the Java Moss from the tank and gently swish it around a bucket of clean water. You may need to repeat this process a few times before putting the plant back in the tank.

In cases where the Java Moss is completely covered and shows signs of suffocation and decay, it is best to discard it altogether. You can still use the anchoring screens and decorations for new pieces of Java Moss. Just be sure to scrub them thoroughly in hot water and let them air dry for at least 24 hours to kill off as much algae as possible. 

When you visit a local pet store, you might be surprised to find that some of the most attractive tanks in the store utilize Java Moss. It can be used to create all kinds of fascinating landscapes while keeping the water in good condition. If you are new to aquatic plants, this is one of the best to get started with.

Where to Buy Java Moss

While you can find Java Moss at most pet stores that carry fish keeping equipment, our preference is Amazon.

Here’s our top recommendation: