Let’s set the record straight before we get going here: one crucial consideration is making sure what you have is java moss. Taxiphyllum Barbieri, formerly Vesicularia dubyana is not Christmas moss (Vesicularia montagnei.) Although it’s commonly suggested that they’re the same plant or have interchangeable common names, they’re not, and they don’t.
Christmas moss isn’t the only name that gets tossed around as a “common name.” Taiwan moss (Taxiphyllum Alternans), willow moss (Fontinalis antipyretica), bladder moss (Physcomitrium pyriforme), flame moss (Taxiphyllum sp.), triangle moss (Vesicularia sp.), and several other mosses have also been suggested as common names for java moss. Again, they’re not the same plants. Every single plant on the above list is a different species.
Are we on the same page now? Java moss is Taxiphyllum Barbieri or even Vesicularia dubyana. Alright, now that we’re all on the same page, this moss might be one of the best low light plants you can buy. You don’t need a substrate to plant it, it doesn’t require intense lights or fertilizers, and it tolerates a wide range of temperatures. It’ll happily attach itself to just about anything but is just as happy floating around your tank.
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Table of contents
Java Moss FAQ
What does java moss do?
Java moss has many uses – from a natural spawn mop to aquascaping, protecting fry from predation to cleaning up water quality by filtering debris.
Does java moss float?
It can float, but it’s worth bearing in mind that you can’t float it in a ball. Instead, spread it out in a thin “sheet” of moss, so all the moss is exposed to light. Otherwise, patches that aren’t exposed to light will rot and die.
Can java moss grow out of water?
Java moss is commonly grown out of water and, in fact, usually is at farms. It grows much faster out of water than in, so most farms that produce it make more money (and faster) by growing it out of water. This practice is the reason when you put your moss in water it usually dies. With that said, it’s a versatile plant for aquariums, paludarium, and vivariums.
Java Moss Natural Habitat
It’s native to Southeast Asia, usually in slow-flowing waters or stagnant pools, and it’s not uncommon to find it growing in blackwater habitats.
Java Moss is considered invasive in some places… according to the internet. However, exactly where those places are is cloaked in ambiguity. Most sites say it’s “considered invasive” but don’t point to scientific research (which seems to be few and far between and difficult to locate) or specific locales. If you know of any credible sources, please let me know in the comments!
Java Moss Care
Difficulty: Easy – melting can be an issue
Size: 4″+ (10 cm)
Propagation: Cuttings
Fertilizer: Liquid
Speed of growth: Moderate
Temperature: 59 – 86F (15 – 30C)
Java Moss tolerates temperatures from 60 – 86 F (15 – 30C) however, it does grow better in cooler waters from around 72 – 76 F (22 – 24C). It tolerates a variety of water conditions, from a pH of 5.0 – 8.0 and soft water from 2 – 12 dKH.
It doesn’t usually need fertilizers, fancy lights, or CO2 injections – which makes it an ideal plant for a low-tech aquascape.
Lighting
Low light tends to be best with java moss simply because of the ever-present algae issues it can develop. If it does develop algae issues, it’s nearly impossible to get it all out of the moss and you’re better off starting over.
Because of this incredibly pesky issue, you’re better off getting a light with a dimmer if you don’t plan on having overhead plants. If you’re looking for a good one, I have a few below.
Substrate & Fertilizers
You’re better off staying away from substarates and fertilizers with java moss. If it’s struggling to adapt to your tank, it was likely grown out of water or was planted too thickly and might need some additional adjustment time. Adding fertz to the water will likely only invite alage issues and make it work.
For Java moss, the most important step is how you attach it to something.
While it does fine floating, it does better when anchored to something – much like java fern. If you know how to anchor java fern (or similar rhizome plants or mosses), the same methods apply for anchoring moss.
Anchoring With Superglue
This is by far my favorite method as I’ve found it to be the least frustrating one. If you want to go this route, find the gel version of superglue. I have used the exact one pictured so I know it’s safe, I cannot make recommendations on other ones since I’ve never used them, but I’ve certainly heard a horror story or two about superglue mishaps from other brands and formulas.
It’s as easy as take your moss, take your object, figure out how you want it to sit on said object, place superglue on the object and place the moss where you want it. I find it easiest to spread the moss in a thin “sheet” before I do this. You’ll need to press the moss in until it starts to grip, and once it’s white, it’s good to go back in the tank. I’ve heard people can superglue plants underwater, but I’ve never attempted to put uncured superglue in a tank, so I can’t advise.
This method is super quick, easy, and gives the aesthetic result you want without a ton of hassle. The downside is that you’ll see the white from the superglue until the moss covers it or it gets covered in mulm (which seems to like to collect on it.)
Anchoring With Fishing Line
The method for fishingline is basically the same as with thread; take your line, wrap it around the moss tight enough to hold the plant in place, but not so tight as to damage it, and – again – pray it holds.
The only difference between the fishing line method and the thread method is that fishing line won’t deteriorate in the water. This is especially helpful if your moss growth is super slow because you can wait until you’re sure it’s anchored rather than wait until the thread decides to disintegrate.
Once you’re sure it’s anchored, you go in and cut the line off. I have had the same issues with fishing line that I’ve had with thread – it wiggles free, it’s never tight enough, it only works well on thin pieces of driftwood, etc.
Anchoring With Thread
I’ve never had much luck with this method, and it only works well(ish) on thin pieces of driftwood. You take your thread, wrap it around the moss tight enough to hold it in place, but not so tight as to not allow it to “breathe,” and hope and pray it holds it.
The idea is, once the moss is fully anchored, the thread will deteriorate in the water and you’ll eventually be left with just well-anchored moss. I’ve always found that when trying to attach moss to rocks, thread will not work. It’ll be too loose in most spots and the moss will eventually wiggle free – or at least some of it – this is especially true if your fish like to inspect the foreign object you just plopped in their personal space. Most do.
Moss Wall
Mosses can attach to basically anything, even foam! Mats and walls are usually too expensive to buy your way there and, if you’re starting from scratch, they take forever to grow in and start out clumpy looking, but the finished result is impressive to say the least. It offers a ton of hiding places for fish and fry and just looks lush and awesome!
If you opt for foam blocks, you can just superglue the thin enough to leave room for growth, secure the blocks (usually with a suction cup or superglue if you want a wall) and you’re done. This is also a great workaround for someone who wants a mat of moss under the substrate – if the foam block is thin enough you can place the substrate around the block to camouflage it and you’re good to go.
You can also sew or superglue some moss onto some craft mesh with the same space idea, although this is a flimsier and more time-consuming option.
Moss Tree
You can make a moss “tree” by attaching your moss to some wood with any of the above methods. Many people opt for bonsai trees (or something like that) but they can be hit or miss. If you’re going for something specific, you can grab some spider wood or glue mini spider wood together yourself. You really won’t see the “branches,” it’s mostly the structure that matters.
I, again, find it easiest to attach the moss with superglue, although you can try tying it, you’re unlikely to get the effect you’re hoping for long-term.
Common Problems
Although it’s an easy plant to care for, it does have a few problems that commonly pop up.
Plant Debris
Plant debris in your tank is a relative problem. If you’re a breeder, your fry and shrimplets will likely enjoy picking off the infusoria and other critters that munch on decomposing plant matter. Similarly, if you have snails, this issue will likely never amount to much. And, so long as you’re not a neat freak, this issue probably won’t bother you.
However, if you don’t fall into one of those three buckets, the mess will probably infuriate you. Additionally, it may cause water quality issues as the plant decomposes and leaches everything it absorbed back into the water.
Clogging Your Filter
Funny thing; aquarium filters. They don’t need large particles to clog, just a lot of small particles. Of course, large floating masses of plants will also clog them.
So as your plant multiplies, sheds, or decomposing plant matter turns into mulm and particulate matter, eventually all of it makes its way to – as you probably guessed – your filter! No matter your filter type; sponge, canister, hang on back, sump, you’ll likely have to up your regular maintenance schedule n your filter.
Melting
Melting is incredibly common in aquatic plants as most of them are grown above water. If you pluck off the dying parts of the plant before they start rotting, the new aquatic growth should appear soon enough, and it’ll do just fine.
Algae
Algae growth is a common problem, it will eventually choke out plants or outcompete them. Algae is a sign of an unbalanced ecosystem, either there is too much light or there are too many nutrients in the water, without one of these opportunities it wouldn’t be able to take hold.
Debris Collection
Mosses and other fine-leafed plants often attract debris that settles and collects within its leafy clutches. This can give it a dirty or brownish appearance and, as we already discussed, most of these types of plants are difficult to clean up. This can be a problem if you don’t have a cleanup crew likes snails, shrimp, or corydoras in your tank as this particulate matter can also – on top of being unsightly – block out light and slowly reduce growth in (or kill) the plant.
Maintenance
It doesn’t require much maintenance, it’s up to you how much work you want (or don’t want) to put in. However, if it starts to become overgrown, it’s best to thin it out some to ensure it doesn’t begin to choke itself.
If you’re trying to create a mat, wall, or tree, it might need a higher level of trimming and shaping as well to keep it looking the way you want.
Propagation
Java moss can propagate through trimmings. Clippings and can be left to float – but be aware they may clog your filter. To start new growth, anchor the clippings in a similar way you did the mother plant. Depending on the size of the clippings, this can be difficult, and you may need to leave it floating until it’s large enough to anchor.
Fish & Java Moss
Java moss can provide shelter for newborn fry, it grows faster than Java Fern, and it’s almost impossible to kill. Shrimp and fry love to graze on the debris the moss collects and the abundance of infusoria that grows on it.
All around it does excellent in a breeding setup since it acts as a spot for foraging, hiding, and spawning. Java moss can also act as a natural water filter. One of the few reported instances of pea puffers spawning in captivity involved moss as a natural spawning mop. Some corydoras also enjoy spawning in this moss. Even if you keep bare bottom breeding tanks, it can be kept floating.
As far as non-breeding setups are concerned, there’s no limit to how you can ‘scape or decorate using java moss. And most species of fish – provided they can go low enough in temperature and prefer calmer water – are great with java moss. Here are a few that I think really shine with it and have fun little quirky behaviors with moss:
Clown Killi (Epiplatys annulatus)
Clown killis, also called rocket killis, are a beautifully colored little fish that come from slow-moving waterways in southern Guinea. They’re usually quite outgoing, but make sure you buy at least eight of them so they can display their social behavior. 10 is even better.
pH: 4.0 – 7.0
dKH: 1 – 8
Temp: 68 – 79F (20 – 26C)
Size: 1.3″ (3 cm)
Temperament: Usually peaceful and active
Swimming: Mid to top
Bettas (Betta Splendens)
Bettas come in a variety of colors, patterns, and I suppose – to some degree – shapes. They’re often quite personable with their owners, and the variation in their personalities makes them fascinating companions.
They don’t do well in fast-flowing waters and require a minimum tank size of 5 gallons (20 liters.)
pH: 6.0 – 8.0
dKH: 1 – 15
Temp: 75 – 82F (24 – 27C)
Size: 2.5″ (6 cm)
Temperament: Varied, but generally highly aggressive towards own kind
Swimming: Everywhere
Norman’s Lampeye Killifish (Poropanchax normani)
Norami killis, or Norman’s lampeye killifish, are non anual killifish (meaning they won’t die in a year) from Central and West Africa. It’s best to get these guys in schools of nine or more to see them at their best. Their blue “eye” nearly glows in the dark and is spectacular to see in person!
pH: 6.0 – 7.0
dKH: 4 – 15
Temp: 73° – 78° F (23° – 26° C)
Size: 1.6″ (4 cm)
Temperament: Peaceful, generally active
Swimming: Mid to top
Corydora (Corydora sp.)
While each species will vary slightly, all require smooth substrates or bare bottom and do best when they’re kept in groups of at least six or more.
Some larger options would be better here, anywhere from 2.5″ (6.5 cm) and up. Good candidates would include bronze, emerald, Sterbai’s, and peppered cories.
pH: 5.5 – 7.0 – species dependent
dKH: 3 – 10
Temp: 72 – 80 F (22 – 26 C) – species dependent
Size: 1 – 3.5″ (2.5 – 9 cm) – species dependent
Temperament: Peaceful, can be boisterous for less active species
Swimming: Bottom (most) in a shoal of 6 or more
Cherry Shrimp (Neocaridina davidi)
Neos enjoy munching on decomposing plant matter, grazing on algae, and picking sunken pieces of wood and plants clean. This makes them a perfect addition to a naturalistic tank. They come in a variety of colors including the oh-so-common cherry shrimp!
pH: 6.5 – 8.0
dKH: 8 – 20
Temp: 70 – 79 F (21 – 26 C)
Size: 1.6″ (4 cm)
Temperament: Peaceful
Swimming: Anywhere there’s food to pick, but usually bottom
Amano Shrimp (Caridina Multidentata)
Most amano shrimp are wild-caught, so you’ll want to make sure you quarantine them properly before adding them to your tank, but they make peaceful and entertaining algae control crew. They’ll be at their best if they’re kept in groups of six or more.
pH: 6.5 – 7.9
dKH: 1 – 6
Temp: 65 – 76 F (18 – 24 C)
Size: 3″+ (7.5+ cm)
Temperament: Peaceful and active
Swimming: Bottom & structured surfaces
Crystal Red Shrimp (Caridina cantonensis)
Crystal red shrimp, not unlike cherry shrimp, come in more colors than just red. They’re a similar size to cherry shrimp and make a great alternative if you’re looking for a little bit more of a challenge. They’re incredibly popular – although more expensive.
pH: 5.8 – 7.4
dKH: 0 – 4
Temp: 62 – 76F (16 – 24C)
Size: 1.25″ (3 cm)
Temperament: Peaceful
Swimming: Surfaces
Black Neon Tetra (Hyphessobrycon herbertaxelrodi)
Not to be confused with the black tetra (or “black skirt” tetras) or neon tetras (Paracheirodon innesi,) the black neon tetra is a separate species. They do best in groups of eight or more – but more is always better when it comes to shoaling fish. They have the peaceful demeanor of the neon tetra without all the health issues.
pH: 5.5 – 7.5
dKH: 4 – 9
Temp: 73 – 81F (23 – 27C)
Size: 1.5″ (3 cm)
Temperament: Peaceful shoaling fish
Swimming: Mid to top
Ghost Shrimp (Palaemonetes paludosus)
Ghost shrimp are usually sold at pet stores as feeders, but they can make great tank inhabitants too! They generally do best in groups of 8 or more and do well with larger fish that won’t eat them. Some very small fish might be eaten by them.
pH: 6.5 – 8.0
dKH: 5 – 10
Temp: 70 – 80 F (22 – 26 C)
Size: 1.5″ (4 cm)
Temperament: Peaceful and active
Swimming: Bottom & structured surfaces
Pencilfish (Nannostomus sp.)
Pencilfish is a genus containing 19 currently recognized species. Some popular options are diptails, Beckford’s, and coral. Although it’s a large genus, the care is similar for all of them and you should aim for a shoal of at least six.
Research into a specific species and their requirements is strongly recommended.
pH: 5.0 – 7.0
dKH: 4 – 12
Temp: 74 – 82F (23 – 27C)
Size: 2″ (5 cm) species dependent
Temperament: Peaceful
Swimming: Mid to top
Neon Tetra (Paracheirodon innesi)
Neon tetras are shoaling fish from the Amazons that are best kept in groups of six or more to be happy. They’re not usually nippy and are active and outgoing if housed properly. They prefer blackwater setups but will do fine in a range of parameters. It’s worth noting that commonly available stock isn’t as healthy or hardy as it used to be even ten years ago.
pH: 4.0 – 7.5
dKH: 1 – 12
Temp: 70 – 83F (21 – 28C)
Size: 1.5″ (4 cm)
Temperament: Peaceful shoaling fish
Swimming: Mid to top
Pea Puffer (Carinotetraodon travancoricus)
If you’re up for a little bit of a challenge, these guys are super rewarding once you put in some work. They’re tiny, smart, curious, personable, and full of sass – plus no salt.
pH: 6.8 – 8.0
dKH: 5 – 25
Temp: 72 – 82°F (22 – 28°C)
Size: 1″ (2.5 cm)
Temperament: Varied
Swimming: Everywhere
Chili Rasboras (Boraras brigittae)
Chilis are tiny. Absolutely minuscule compared to your average aquarium fish. They’re also shoaling fish that need to be kept in groups of at least 10 – but, again – they’re tiny! Even still, they pack a colorful punch once settled in and make a beautiful, active display for the right tank.
pH: 4.0 – 7.0
dKH: 1 – 10
Temp: 68 – 83F (20 – 28C)
Size: .5″ (1 cm)
Temperament: Peaceful shoaling fish
Swimming: Mid to top
Toucan Tetras (Tucanoichthys tucano)
These guys are hard to find (but I know a few good spots if you want them!) And they’re completely worth hunting down these rare gems. They’re a peaceful shoaling fish that need to be kept in groups of six or more and the only known wild population exists within a 200-meter range in Brazil.
pH: 4.0 – 6.5
dKH: 1 – 8
Temp: 68 – 83F (20 – 28C)
Size: 1″ (2 cm)
Temperament: Peaceful shoaling fish
Swimming: Mid to top
Further Reading & Resources
Aquascape Addiction – Java moss: how to grow carpets, walls, trees, and more
Aquascaping Love – A Guide to Keeping and Growing Aquatic Moss