How to Grow Java Moss in A Fish Tank

By Eddie Waithaka @aquariawise

Learn How to Grow Java Moss in Your Aquarium

There are many kinds of beautiful mosses, but Java moss is the most readily available and least expensive, though there are a million other reasons why it’s most popular of all freshwater aquarium plants.

The plant doesn’t require too much attention and accepts a wide range of water condition including brackish water, and is also not fussy about light quality.

Java moss is especially useful to aquarist raising fry to protect them from cannibalistic adults.

Aesthetically, Java moss makes a good foreground plant and can be easily attached to rocks, driftwood, and roots. Due to this clinging nature, it even folds on nets to form beautiful moss walls, carpets, and trees. Plus it’s easy to propagate through cuttings.

Genetically, the plant belongs to the Hypnaceae family native to Southeast Asia and commonly used in freshwater aquariums. It forms small, green leaves that rarely grow big, and develops in pairs on each side of the stem.

Java moss grows best in not so warm conditions but can tolerate up to 85°F.

To better understand Java Moss culture in aquaria environments, in this article we’ll look at the Uses, Care and Propagation of Java moss.

What Does Java Moss Do?

Between it’s characteristic attaching tendencies, ease of propagation and flexible growing conditions, Java moss can be used in a couple of different ways in aquariums.

From creating beautiful aquarium aspects through moss walls, trees, and carpets. To sheltering young fry and even feeding shrimp that like to nibble on the miniature leaf-like structures called phyllids.

And generally, fish love Java moss.

Let’s see 2 popular uses of Java Moss.


Aquascaping is the craft of arranging plants as well as rocks, stones or driftwood in an aesthetically pleasing manner within an aquarium setup.

Java moss can be used to aquascape together with rockwork and other hardscapes.

In fact, the plant is one of the easiest to grow in an aquascape and is great for beginners ready to get their hands wet.

The best way to use Java Moss is as a foreground plant. Tie your plants on rocks, stones or driftwood and spread it to form a low lying moss vegetation commonly called a moss carpet.

Over time, the cotton threads you will use to tie the plant will decompose but leave the moss established.

However, moss carpets are attractive but will need regular trimming. Maybe once every week or two.

Java moss can also be made into a moss wall, this is accomplished by folding a net and spreading the moss evenly across it.

The net is then secured together with polyester strings and held on the aquarium using suction cups. It will start slowly but will eventually establish.

Another aquascaping option is a Java moss tree, though a little harder to make, it’s nonetheless not uncommon.

You will need to add the bottom end of driftwood that’s sturdy enough to hold the moss into your aquarium substrate. Then attach Java moss on top of the driftwood and let it grow.

However, if you don’t insert the bottom of the tree into your aquarium substrate properly, you will end up with the moss lifting the driftwood as it grows.

Though moss is quite easy to grow as it is undemanding, you will need to add CO2 and fertilizer for your aquascape to thrive. Also, under low lighting, Java moss will grow fairly light in color with fronds sparsely spaced.

The last way to bring life to your aquarium with Java moss is through Java moss balls. They are tiny, easy-to-move and great for water quality in smaller tanks.

You can DIY the balls but if you need both the Java moss and the ball, buy them premade. Which is usually cheaper and realistic if you are a beginner.

Java Moss is Perfect for Breeder Tanks

Many fish species spawn among Java moss plants in the aquarium even when it can not be found in their native habitat, and the plant also serves as the first home to many freshwater newborns.

Java moss will sometimes act as both a natural food source to fry, as well as a place to hide from adult fish where it’s mostly used to raise shrimp and guppies.

The more moss you have, the higher the fry survival rate.

In somewhat of a symbiotic relationship, Java moss provides food to shrimp, in turn, the inverts delicately clean the moss ensuring it stays healthy, especially when hair algae growing on the moss.

What Java Moss Needs to Grow

Generally, Java moss is relatively easy to install, care for and will grow adequately even with what is considered a harsh aquarium condition.

It’s, therefore, a great plant for beginners and is compatible with most fish.

If you are looking to start Java moss in your aquarium, this is everything you’ll need to know.


All plants need water to grow, and Java moss is no exception especially now that it’s an aquatic species.

However, it cannot survive for long in marine aquariums, so make sure you have a freshwater tank.

The plant prefers soft acidic water which is fresh with a moderately cool temperature. An aquarium environment anywhere between 70°F and 75°F and a pH of 5.0 to 8.0 is good enough.

However, Java moss will survive in slightly brackish water with low salt content. Tap water should work fine as well, but you may need to add chemicals from an aquarium store to make it safe for your plants and fish.

Java moss is also best suited in moving water, with some hobbyist even growing the plant outside the tank in small, fast moving creeks or waterways.

So, make sure the water in your tank is constantly circulating or your plant won’t get enough nutrients and start to wither.

Besides, apart from helping your plant thrive, a well-circulated aquarium helps reduce debris that gets stuck on the plant and give it a brown fuzzy appearance. Which is everything but beautiful.

Even so, the moving water also carries loose Java moss debris into the aquarium filter intake, which with time, may clog and sometimes even damages the filter.

To keep this from happening, you will need to be cautious, especially if your plant is not anchored in the substrate, rocks or driftwood, but floats on the water instead.

Another brilliant chop is to keep a good cleaning schedule that includes weekly vacuuming. This ensures food debris, plant particles, and fish waste doesn’t remain in the water or gets stuck on the plant.


Like water, all plants need light to photosynthesize and grow, so the only difference between Java moss and other aquarium plants is that it doesn’t need a lot of it.

The plant is one of the few that will grow in low light conditions, and in some instance, it will survive with almost no light. Although the plant won’t necessarily flourish, it won’t die either.

However, the more light you have, the faster the growth.

That said, Java moss will do best in medium light, which is anywhere between 2 and 4 watts per gallon of fluorescent grow light.

In regard to your aquarium lighting fixture, you won’t require any sophisticated add on, average T5 fluorescent bulbs or any specific LED grow light should do. However, incandescent bulbs are not the best and only use metal halide bulbs if you have a big aquarium.

Having said that, if your plant is covered in algae, the most likely culprit is too much light. You should, therefore, only use strong lights if you’re C02 or nutrient dosing, otherwise, your aquarium will turn into an algae farm.

Co2 and Nutrient Dosing

Just like water and lights needs, no fancy CO2 and nutrient dosing are required, but any effort will pay off.

You will only need to add CO2 and fertilizer if you need to speed up your Java moss growth, where periodic feeding with liquid fertilizer will promote new growth and keep your plant healthy.


Although the size is not a big issue in a Java moss tank, any aquarium that’s smaller than 5 gallons will shrink once the moss starts to grow, which, in turn, will reduce the space available for your fish.

Keep a filter in the tank to provide water circulation (as mentioned before) to help your plant thrive, as well as clean your tank, and ensure your plants get nutrients adequately.

Even so, once the moss roots are established, weaker water current is best because a stronger one will break the moss apart.

You will also need to regularly check the water pH to make sure it’s between 5 and 8.

In case the pH gets too low, adding shells and rocks in your tank can help raise the pH.

Java Moss Care

As I had mentioned before, Java moss is extremely easy to grow and maintain, and so, the biggest hurdle you may encounter is algae growth.

Unfortunately, once the growth starts, it almost impossible to completely remove, and you may have to discard the whole plant.

Usually, algae is caused by either of two reasons. The first and major cause is too much light, albeit the plant growing a bit quicker. Under bright light, Java moss will also collect algae much quicker.

Ergo, the best remedy is to use either low-lights or medium lights if your aquarium room is too dark.

Reason number two is elevated nitrates and phosphate, which tend to creep up when water changes aren’t performed regularly. So, to discourage the algae, a filter is paramount, plus a regular cleaning schedule that includes cleaning your gravel.

Another not so conventional approach is flourish-excel.

Although the additive is purposed to inject C02 into tanks, many hobbyists have also found it very effective at killing off stubborn algae. In severe cases, it can even be applied directly to the affected areas with a syringe.

One last remedy: you can use is keeping algae eaters like shrimp in your Java moss tanks. Fish like bristlenose plecos, Siamese Algae eaters, mollies and snails like Malaysian trumpet snail, nerite snail and mystery snail are good candidates.

Growth and Propagation

Java moss is a slow to medium growth and is mostly propagated through division.

Given the proper conditions, simply breaking off a piece and attaching it somewhere else is all it takes to get a new plant.

The division should start growing in just a couple of days after it’s properly attached.

Propagating through divisions is particularly useful if you live in a place where the plant is not readily available hence tend to get quite pricey.

To best propagate your Java moss, proper light, and CO2 and fertilizer dosing is recommended. Also, the moss tends to grow better in fairly cool and well-circulated water.

In case your plant grows too rapidly and max out your tank, it’s fairly easy to trim the spreading parts which would normally grow horizontally or vertically depending on the orientation.

Java moss plant divisions usually attach via root-like rhizoids which do not absorb nutrients as roots and stems do. Therefore nipping them is the best way to slow down the spread.

Growing Java Moss Aquascapes

When aquascaping with Java moss, the most common choice is a moss carpet and the Java moss wall second. A moss tree is the most challenging to grow, so I’d recommend you try it if you have a lot of time and willing to experiment.

Java Moss Carpet

In order to plant a carpet correctly, make sure you anchor it on a flat, non-floating object. The best moss carpet layout uses character driftwood pieces or aquarium rocks.

The moss should be tied either with cotton thread or a light fishing line. However, cotton threads will rot after a week but should leave the moss well in place.

If you are concerned that the cotton will rot before the moss is properly attached, use a fishing line which does not rot.

Generally, go with clear color threads or lines which are not conspicuous to keep the aesthetics perfect, even before the plant covers the driftwood or rock surface fully.

There are many ways you can layout your driftwood, but Id recommends you attach the moss where the wood divides and around the base.

Other people pin the carpet down the substrate using a mesh net or sprinkle a layer of substrate on the moss and let it grow right through.

Whichever method you opt for, just make sure your moss is weighed down and secure. You can even use rubber bands, zip ties or specialty plant super glue.

Java Moss Wall

Moss walls mostly embellish aquarium glass, which you can do using plastic mesh and suction cups to hold the netting on the tank surface.

The quickest method involves using a net folded in half then attaching it on the aquarium with suction cups, and stuffing the moss inside each end.

As with driftwood, the moss can be tied to the mesh with clear cotton thread or fishing line.

Java moss walls usually grow faster than moss carpets, due to the fact that they don’t have anything blocking their light source. Therefore, although the moss wall will hide unnatural looking grass with a living coat, regular trimming is needed for a neat compact covering.

Plus you won’t leave your aquarium looking cramped.

Java Moss Tree

Growing a Java moss tree involves using a piece of driftwood with several branches, small natural sponges and specialty plant super glue.

The branches are glued on the gaps of the branches and then the moss glued on to the sponges. As the moss starts to grow, you will then trim it accordingly to achieve the desired tree shape.

Some people also use bamboo skewers and tie Java moss on with the cotton thread. When the moss grows out a little, they trim it back and continue doing that till after a few cuttings the skewer looks like a tree.

A third option is to use three pieces of wood which when combined look like a big tree. Anchor the biggest piece in the substrate and use it for the trunk where the other two pieces branch out.

It is important to attach the moss in a way that it’s spread will naturally attach to the small branches. If you don’t do that, the moss strands will end up free floating which will make it difficult to trim.

It’s also important to have the moss mass attached to several parts of the branches because the undergrowth may become weak and die when the moss starts to spread and layer.

FAQ About Java Moss

Now, let’s see a few frequently asked question.

Is Java Moss Fast Growing?

Generally, Java moss is slow to the average growing plant, but the growth rate does depend a lot on light and dosing.

Moss growing in low light, less than 1.5 watts per gallon of fluorescent light, will grow a bit slower than moss grown in medium light. Which is 2 to 4 watts per gallon of fluorescent glow light.

Java moss with regular CO2 and nutrients dosing will also grow quite fast compare. Plus other proper conditions like well circulated and clean water.

However, be careful as too much light will help algae grow in equal measures.

How to Encourage Java Moss to Spread

Periodic feeding with liquid fertilizer will promote new growth and keep the most healthy and spreading continually.

It’s also helpful to attach your moss in a way that allows it to spread. Encourage the root-like structures grip on to spaces by adding cotton strings or fishing line along the spread area.

Reduce the frequency of trimming your moss as well.

Java moss with unobscured light exposure like moss walls will spread faster than moss carpets that are not properly illuminated, so exposing your Java moss to light should, therefore, increase the spread.

Have Fun Aquascaping!

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