Not a moss and not a plant, and the first alga in a silo called aquarium plants
Marimo moss balls are algae. Every source we hold says so, and the common name is wrong in both of its words. This site already holds twelve records whose diet row names algae, four of which exist specifically to remove it. This is the first record here about buying it.
Aquarium Store Depot: marimo moss balls are a species of filamentous green algae called Aegagropila linnaei. Aquarium Breeder: marimo moss ball is a type of green algae, and technically not a true moss. Aquarium Care Basics: a Marimo Moss Ball is a form of green algae that looks like a plant.
Wikipedia goes one level further and it changes what the record is about. Marimo is a rare growth form of the species, not the species itself, and the alga takes three forms: growing on rocks, typically on shaded sides; existing as free-floating filaments forming carpet-like layers; and forming the spherical balls, where the algae grow into sizable balls of densely packed algal filaments that radiate from the center.
So a marimo moss ball is one of three shapes a single alga makes, and the ball is the rare one. Wikipedia places the species in the areas of Europe previously covered in glaciers and in several places in Japan, and adds the fact that reframes the whole purchase: the marimo has been a protected species in Japan since the 1920s, and in Iceland since 2006.
Why this record was written now
- The gap
- Three thousand three hundred searches a month for an organism whose common name gets its kingdom wrong, sold in a silo of true plants.
- What it changes
- The first alga here, the slowest growth rate on the site, the first pH row that meets at a single value, and the first station whose instructions come from a government agency.
- What it does not
- No hardness row, because the plant schema does not carry one, and no lifespan row, because the sources disagree by an order of magnitude.
Four sources, four names, and one still uses the genus DNA work retired in 2002
| Name | When | Who uses it |
|---|---|---|
| Aegagropila | 1843 | Established by Friedrich T. Kützing, on Wikipedia |
| Cladophora, subgenus Aegagropila | before 2002 | Aquarium Care Basics, as Cladophora Balls |
| Aegagropila linnaei | 2002, after DNA research | Aquarium Store Depot, Aquarium Breeder, and this record |
| Aegagropila brownii | current on Wikipedia | Wikipedia |
Read the table top to bottom and it is a single organism moved four times. Wikipedia gives the sequence: the genus Aegagropila was established by Friedrich T. Kützing in 1843, then all the Aegagropila species were transferred to subgenus Aegagropila of the genus Cladophora, then extensive DNA research in 2002 returned the name to Aegagropila linnaei. It now gives the accepted name as Aegagropila brownii.
The second row of that table is the one worth stopping on. Aquarium Care Basics offers Cladophora Balls as an alternative name, and Cladophora is the genus this organism was moved out of more than twenty years ago. That is not a competing scientific opinion, it is a care sheet that has not been revised, and it is worth knowing when the same page is the only one of three that says the light level can be high.
This record prints Aegagropila linnaei because that is what the two aquarium sources with a binomial use and what a shop label will say. It names brownii because our reference source now prefers it. Following the trade for the row and the reference source for the note is the opposite of what our celestial pearl danio record does, where the trade name was wrong about the family and the record refused it. The difference is that here the trade name is out of date rather than incorrect.
What none of the four disputes is the kingdom. Green algae on all four, not a moss on three of them explicitly. Marimo itself is a Japanese word rather than a taxonomic one, and Wikipedia treats it as the name of the growth form rather than of the species, which is why this record is titled for the ball and named for the alga.
Five millimeters a year, and the fastest grower on this site is in the same silo
| Record | Published growth rate | Measured or described |
|---|---|---|
| Marimo moss ball | 5 mm a year, about 1 in every 5 years | Measured, on three sources |
| Java fern | Slow. A new leaf in two to four weeks | Measured |
| Anubias | Slow. 1 to 2 leaves in about three weeks | Measured |
| Java moss | Medium | Described |
| Amazon sword | Moderate | Described |
| Water sprite | Fast | Described |
| Water wisteria | Fast, on every source | Described |
| Hornwort | 1 to 4 in a week | Measured |
Three sources publish a growth rate for this organism and all three publish the same figure. Wikipedia: the growth rate of marimo is about 5 mm, 0.2 in, per year. Aquarium Store Depot: marimo balls grow 0.20 inches, 5 mm, every year, which it converts to 1 inch, 2.5 cm, every 5 years. Aquarium Breeder gives the same 5 mm and types it slow to moderate.
Put the two ends of that table together and the silo covers a range no other row on this site approaches. Our hornwort record publishes 1 to 4 inches in a week. At the slow end of hornwort and the only end of a moss ball, hornwort grows in seven days about five times what the marimo grows in a year. Both are in the same silo, both need no CO2, and both tolerate 59 °F or below on at least one source.
The growth rate is also the reason for two other rows on this record, which is unusual: normally a growth figure is a fact and not a cause. It is why Aquarium Store Depot says it is usually easier to buy another moss ball than it is to propagate one, because a split half has to regrow its shape at five millimeters a year. And it is why no source asks for CO2 or fertilizer: Aquarium Breeder types both not needed, low, because nothing growing at this rate has a nutrient bottleneck.
On maximum size the sources split by habitat rather than by opinion, which is the useful kind of disagreement. Aquarium Store Depot says that in aquariums they stay under 5 inches, 12.7 cm, in diameter. Aquarium Breeder gives a wild maximum of 20 to 30 cm or 8 to 12 inches, and Wikipedia the same range. Aquarium Care Basics says they are typically sold around 2 inches in diameter and can be found upwards of 5 inches around. At 5 mm a year, the gap between a shop marimo at 2 inches and a wild one at 12 is roughly fifty years of growing.
The full record
| Field | Recorded | Where it comes from |
|---|---|---|
| Light | Low to moderate, and direct light burns it | Three sources publish a light level and two of them agree against the third. Aquarium Store Depot: keep marimo moss balls out of direct, intense aquarium lighting, with low to moderate conditions and at least 7 hours a day. Aquarium Breeder gives low to medium and the same warning: intense lighting from direct sunlight exposure and high-intensity LED lighting will harm the balls. Aquarium Care Basics disagrees and gives wide range, low to high light. The row follows the two that agree, and the reason to trust them is in Wikipedia rather than in either: the wild form grows on rocks, typically on shaded sides and at the bottom of lakes. This is the lowest light requirement in the plants silo, alongside our java moss and anubias records, and the failure mode at the top of the range is the same one those two carry: brown patches rather than burn. |
| CO2 | None, and no source asks for any | The shortest row on this record and the only one with no disagreement at all. Aquarium Breeder types both CO2 and fertilizer as not needed, low, and notes they help keep the ball healthy without being essential for an extremely slow-growing organism. Aquarium Store Depot says no CO2 injection is necessary and that fertilizer is optional, since the ball survives on nutrients from fish waste. Aquarium Care Basics does not raise the question. Nothing that grows five millimeters a year has a CO2 requirement, and this is the one row where the growth rate makes the answer obvious rather than difficult. |
| Placement | The bottom, and turn it weekly | Two sources put it on the bottom and one puts it further forward. Aquarium Store Depot: they typically rest on the bottom of the tank but work on various surfaces. Aquarium Care Basics: they stay on the tank bottom or can float, and a Marimo Moss Ball will find a spot and stay there. Aquarium Breeder gives foreground / midground. The row follows the two that agree and the instruction attached to it is the one every source shares: rotate it. Store Depot says to turn it about every week during water changes and to gently squeeze with old tank water to remove trapped detritus. Wikipedia explains why that is not optional, because in the wild the round shape of the marimo is maintained by gentle wave action that occasionally turns it. A moss ball in a tank has no waves, so the keeper is the wave. |
| Substrate | Irrelevant, and one source prefers gravel to sand | Both sources that address it say the substrate does not matter, which makes this the fourth answer this silo has to the same row. Aquarium Store Depot: substrate type, gravel, sand or bare bottom, does not matter. Aquarium Breeder types it not needed and then adds the one practical preference on this record: gravel is preferred over sand to prevent entanglement during cleaning. That is a reason about handling the ball rather than about feeding it, which is what you would expect from something with no roots at all. For the rest of the silo, our amazon sword record makes the substrate a requirement, our java fern and anubias records make it irrelevant because both are tied to hardscape, and our water wisteria record splits. |
| Growth rate | 5 mm a year, about 1 in every 5 years | Three sources publish a growth rate and all three publish the same one. Wikipedia: the growth rate of marimo is about 5 mm, 0.2 in, per year. Aquarium Store Depot: marimo balls grow 0.20 inches, 5 mm, every year, which it converts to 1 inch, 2.5 cm, every 5 years. Aquarium Breeder types it slow to moderate and gives the same 5 mm. That is the slowest growth any record on this site publishes, and the comparison worth making is inside this same silo: our hornwort record publishes 1 to 4 inches in a week. At the low end, hornwort grows in seven days about five times what a moss ball grows in a year. On maximum size the sources split by habitat rather than by opinion: Store Depot says that in aquariums they stay under 5 inches, 12.7 cm, in diameter, while Aquarium Breeder gives a wild maximum of 20 to 30 cm or 8 to 12 inches and Wikipedia the same range. Aquarium Care Basics says they are typically sold around 2 inches in diameter. |
| Propagation | By splitting and re-rolling, or buy another | Two sources describe the method and one of them recommends against bothering. Aquarium Breeder gives it plainly: splitting and re-rolling them are the primary methods. Aquarium Store Depot describes the same thing and then says the quiet part: it is usually easier to buy another moss ball than it is to propagate one, because cutting one in half and reshaping it is possible but slow. That is the growth rate row restated as advice. A half ball has to regrow its shape at five millimeters a year, so a split that costs nothing in effort costs years in appearance, and this is the only record in the plants silo where a source suggests buying rather than propagating. For contrast, our water wisteria and hornwort records propagate from a cut stem in weeks. |
| Temperature | 72 to 75 °F | Three bands and they meet in three degrees, and the outlier is remarkable. Aquarium Care Basics gives 72 to 78 F. Aquarium Store Depot gives 65 to 80 F, 18 to 27 C. Aquarium Breeder gives 43 to 75 F, 6 to 24 C, which is the lowest temperature floor any record on this site publishes, well under the 59 °F our java moss and hornwort records carry. The row prints the 72 to 75 all three contain. What the sources do agree on is the failure at the top: Store Depot warns that above 82 °F the balls develop brown spots, and that overheating can make them fall apart entirely. So the ceiling is the dangerous end and the floor is the one a Japanese lake supplies, which is consistent with an organism Wikipedia places in areas of Europe previously covered in glaciers and in Japan. |
| pH | 7.0, the only value both bands contain | This is the site method taken to its limit. Two sources publish a pH range and they overlap at exactly one value. Aquarium Store Depot gives 6.5 to 7.0. Aquarium Breeder gives an optimal 7.0 to 8.0. The only figure both contain is 7.0, so that is the row, and printing a range here would mean choosing one source over the other without a reason. Aquarium Care Basics declines the question and gives wide range, can be slightly acidic or on the alkaline side, which is the honest version of what the disagreement implies. On hardness Aquarium Breeder says very soft to very hard, and the plant schema on this site carries no hardness row, so that figure is recorded here rather than in a row of its own. In practice this is a wide-tolerance organism whose two numeric sources happen to sit on opposite sides of neutral, and 7.0 is where they touch. |
| Eaten by | Plecos and crayfish, with goldfish as a caution | Two sources name animals and they agree on the one that matters. Aquarium Store Depot says to avoid pairing with plecos, crayfish, and cautiously with goldfish and cichlids. Aquarium Care Basics names one: goldfish may be interested in it as a food source, and adds the distinction that shrimp and snails feed on food particles trapped in the ball rather than on the ball itself. That second half is why this row is shorter than it looks: a moss ball collects detritus, so a shrimp or a snail sitting on one is grazing what the ball caught rather than eating the ball. On our own records the animals named are all written here: our goldfish, common pleco and bristlenose pleco records, and crayfish has no record here yet. Goldfish is the fourth plant record on this site to name it, after our amazon sword, water wisteria and water sprite records, so on this site goldfish is the most frequently refused animal in the plants silo. |
The same nine fields for every animal on this site are in the A to Z index.
Where our sources disagree
Every record here names a disagreement. On this one four sources give four versions of the name, and one of them uses a genus that DNA research retired in 2002.
Wikipedia, on the current name
Aegagropila brownii; extensive DNA research in 2002 returned the name to Aegagropila linnaei
Aquarium Store Depot, on the same organism
a species of filamentous green algae called Aegagropila linnaei
Aquarium Care Basics, still on the old genus
Cladophora Balls
What we record: we print Aegagropila linnaei and name what Wikipedia now prefers. The two aquarium sources that give a binomial both use linnaei, which is the name the 2002 DNA work produced and the one the trade adopted.
Wikipedia has since moved to Aegagropila brownii, and this record follows the trade for the row and the reference source for the note, because a keeper searching a shop label will not find brownii. The third source is the interesting one.
Aquarium Care Basics offers Cladophora Balls as an alternative name, and Cladophora is the genus this organism was moved out of more than twenty years ago. That is not a competing opinion, it is a care sheet that has not been updated.
What no source disputes is the part that matters most: every one of them says this is filamentous green algae rather than a moss or a plant, which makes the common name wrong in both of its words.
March 2021, and the only instructions on this site written by a government agency
On 2 March 2021 this stopped being a care question. The US Fish and Wildlife Service records it precisely: on March 2, 2021, the U.S. Geological Survey confirmed a report from a Seattle pet store of zebra mussels attached and inside moss balls. Wikipedia dates the same notification to the same day.
It spread as fast as the retail chain that carried it. As of April 27, 2021, zebra mussel contaminated moss balls were discovered in 46 states. Zebra mussels are one of the most damaging freshwater invasives in North America, and the Service gives the reason: they can reach extremely high densities and quickly take over a waterbody, disrupting food chains, smothering native mussels, clogging infrastructure and altering water chemistry.
No record on this site has previously mentioned zebra mussels, and this is the only station on any marimo page here whose instructions are an official response rather than a care recommendation. Our goldfish record already cites USGS, so a government source is not new; an agency telling owners to destroy a product they bought is.
The three approved methods, verbatim
- Freeze
- Place the moss ball into a sealable plastic bag and freeze for at least 24 hours.
- Boil
- Place the moss ball in boiling water for at least 1 full minute.
- Bleach or vinegar
- Submerge the moss ball in regular, unscented bleach, diluted to one third cup per gallon of water, for 10 minutes; or undiluted white vinegar for 20 minutes.
- Then dispose
- Dispose of the moss ball and any of its packaging in a sealed plastic bag in the trash. Never down a drain, into a waterway, or onto a garden.
Two things about that list are worth naming. The first is that all three methods kill the marimo, which is the point: the guidance is for a product suspected of carrying an invasive animal, not a cleaning routine. The second is that Aquarium Store Depot, writing later, gives a much softer version of the same event: in 2021, zebra mussels were discovered living inside store-bought marimo balls, with the advice to rinse new balls with old tank water before adding them. Rinsing is not on the Service’s list.
The outcome was better than the scale suggests, and it belongs here because a record that prints an alarm should print the resolution too. Efforts to stop the sale and pull contaminated stock succeeded, and to the best of the agencies’ knowledge no zebra mussel introduction into a waterbody resulted from the incident.
The keeper is the wave, and that is most of what this organism needs
Wikipedia explains the shape in one sentence and it is the whole of the maintenance instruction: the round shape of the marimo is maintained by gentle wave action that occasionally turns it. A lake supplies that. A tank does not. So the keeper is the wave, and every source that discusses care says the same thing in practical terms.
Aquarium Store Depot: rotate it about every week during water changes, and gently squeeze with old tank water to remove trapped detritus. The reason to turn it is that the underside browns, which is the same failure the light row produces from the other direction: too much light on top, none underneath.
On light, two of three sources agree and the third is the one still using Cladophora. Store Depot: keep marimo moss balls out of direct, intense aquarium lighting, with at least seven hours a day. Aquarium Breeder: low to medium, and intense lighting from direct sunlight exposure and high-intensity LED lighting will harm the balls. Aquarium Care Basics gives wide range, low to high light. Wikipedia settles it from the habitat rather than the tank, placing the wild form on rocks typically on shaded sides and at the bottom of lakes.
The temperature row is where the sources spread widest and the outlier is the interesting one. Aquarium Care Basics gives 72 to 78 °F, Aquarium Store Depot 65 to 80, and Aquarium Breeder gives 43 to 75 °F, 6 to 24 C. Forty three degrees is the lowest temperature floor any record on this site publishes, below the 59 °F on our java moss and hornwort records. The row prints the 72 to 75 all three contain.
What they agree on is the ceiling and the consequence of passing it. Store Depot warns that above 82 °F the balls develop brown spots and that overheating can make them simply fall apart. An organism from glacial lakes in northern Europe and from Japan has a cold end that is not the problem and a warm end that is.
The last row is the animals, and the pattern on this site is now clear enough to state. Store Depot says to avoid plecos, crayfish, and cautiously with goldfish and cichlids; Aquarium Care Basics says goldfish may be interested in it as a food source. That makes goldfish the most frequently refused animal in this silo, named by our amazon sword, water wisteria, water sprite and now this record. Aquarium Care Basics adds the distinction that saves the shrimp: they feed on trapped food particles rather than consuming the moss ball itself.
What a marimo actually does for a tank, and the source that claims a benefit and then takes most of it back
Marimo moss balls are sold on function as much as on appearance, and Aquarium Breeder is the only source we hold that lists the functions and then argues with its own list. It is worth reading in that order.
The claims first. On oxygen: just like other aquatic plants, Marimo uses up CO2 and provides oxygen in the tank as a result of the photosynthesis process. On filtration: the unique structure of moss balls harbors a good amount of beneficial bacteria and helps with cycling a tank. On waste, which is the claim no true plant in this silo can make: Marimo Moss balls do not produce any waste in the tank, unlike other plants that do shed their leaves which fall to the bottom of the tank and rot thereby polluting the tank water.
Then the same source removes most of the value from two of them, and the reason is the growth rate. On nitrate reduction it calls the effect a small bonus and explains why: they grow very slowly. As a result, their consumption rate is also pretty low. On outcompeting nuisance algae it says the effect is mostly possible in smaller tank set-ups and cautions against relying on it. Five millimeters a year is not a nutrient sink.
The function that survives its own scrutiny is the one about shrimp, and it is the best argument for a marimo in a tank that has any. Marimo moss balls serves as grazing or foraging ground for inverts and small fish. Tiny bits of food get trapped in the algae filaments which the shrimp can graze on, which Aquarium Breeder connects to improved survival among shrimplets.
That reading also settles what looked like a conflict in the eaten by row. Aquarium Care Basics says shrimp and snails feed on trapped food particles rather than consuming the moss ball itself, and Aquarium Breeder describes the same behavior as a benefit rather than a risk. The two sources are describing one thing from opposite ends: a ball of dense filaments is a sieve, and what a shrimp eats off it is what the tank put there.
Aquarium Breeder names the shrimp it considers compatible and the list is broad: Neocaridina, Caridina, amano, ghost, bamboo and vampire shrimp. Four of those six have records on this site, our cherry shrimp record as Neocaridina davidi, our amano shrimp record as Caridina multidentata, and our ghost shrimp record. All three publish a pH band that contains the 7.0 on this record, which for once makes the pairing arithmetic trivial.
So the honest summary of a marimo moss ball as equipment is narrow and real: it adds no waste, it holds bacteria, it feeds shrimp what the tank drops, and it will not measurably clean your water because it barely grows. Every one of those follows from the same figure in station 03.
Marimo moss ball questions, answered from the record
Are moss balls plants or algae?
Algae, and every source we hold says so. Aquarium Store Depot: marimo moss balls are a species of filamentous green algae called Aegagropila linnaei. Aquarium Breeder: a type of green algae and not a true moss. Aquarium Care Basics: a form of green algae that looks like a plant. The common name is wrong twice over, and this is the first alga in a silo of seven true plants.
What is the scientific name of a marimo moss ball?
Four sources give four versions. Wikipedia currently gives Aegagropila brownii and traces the history: the genus was established in 1843, moved into Cladophora, then extensive DNA research in 2002 returned the name to Aegagropila linnaei. Aquarium Store Depot and Aquarium Breeder both use Aegagropila linnaei, which is what this record prints. Aquarium Care Basics still lists Cladophora Balls, which is the genus the 2002 work moved it out of.
How fast do moss balls grow?
5 mm a year, which is about one inch every five years, and three sources publish the same figure. That is the slowest growth rate any record on this site carries. For scale, our hornwort record publishes 1 to 4 inches in a week, so hornwort grows in seven days roughly five times what a moss ball grows in a year, and both are in the same silo.
How big do moss balls get?
It depends whether you mean a tank or a lake. Aquarium Store Depot: in aquariums they stay under 5 inches, 12.7 cm, in diameter. Aquarium Breeder gives a wild maximum of 20 to 30 cm or 8 to 12 inches and Wikipedia the same. Aquarium Care Basics says they are typically sold around 2 inches in diameter. At 5 mm a year, the gap between a two inch shop ball and a twelve inch wild one is roughly fifty years of growing.
Do moss balls need a light?
Low to moderate, and two of three sources warn against more. Aquarium Store Depot: keep marimo moss balls out of direct, intense aquarium lighting, with at least seven hours a day. Aquarium Breeder: low to medium, because intense lighting from direct sunlight exposure and high-intensity LED lighting will harm the balls. Aquarium Care Basics disagrees and gives wide range, low to high light. Wikipedia supports the majority from the habitat: the wild form grows on rocks typically on shaded sides.
Do moss balls need CO2 or fertilizer?
No, and this is the only row on the record with no disagreement at all. Aquarium Breeder types both as not needed, low. Aquarium Store Depot says no CO2 injection is necessary and fertilizer is optional, since the ball lives on nutrients from fish waste. Nothing that grows five millimeters a year has a nutrient bottleneck.
What pH do moss balls need?
7.0, and that is the only value both published bands contain. Aquarium Store Depot gives 6.5 to 7.0 and Aquarium Breeder gives an optimal 7.0 to 8.0, so the two overlap at exactly one figure. Aquarium Care Basics declines a number and says wide range, can be slightly acidic or on the alkaline side, which is probably the fairest description. On hardness Aquarium Breeder says very soft to very hard.
What temperature do moss balls need?
72 to 75 °F, the span all three published bands contain, and one source goes remarkably low. Aquarium Care Basics gives 72 to 78, Aquarium Store Depot 65 to 80, and Aquarium Breeder 43 to 75 °F, which is the lowest temperature floor on this site. The dangerous end is the top: Store Depot warns that above 82 °F the balls brown, and that overheating makes them simply fall apart.
Why do you have to roll or squeeze a moss ball?
Because a tank has no waves. Wikipedia: the round shape of the marimo is maintained by gentle wave action that occasionally turns it. In an aquarium the keeper supplies that. Aquarium Store Depot says to rotate it about every week during water changes and to gently squeeze with old tank water to clear trapped detritus. Skip it and the underside browns.
How do you propagate a moss ball?
By splitting and re-rolling them, on Aquarium Breeder, and Aquarium Store Depot recommends against bothering: it is usually easier to buy another moss ball than it is to propagate one. That is the growth rate restated as advice, because a split half regrows its shape at five millimeters a year. This is the only record in our plants silo where a source suggests buying rather than propagating.
What happened with zebra mussels and moss balls?
On March 2, 2021, the U.S. Geological Survey confirmed a report from a Seattle pet store of zebra mussels attached and inside moss balls, and as of April 27, 2021, zebra mussel contaminated moss balls were discovered in 46 states. The US Fish and Wildlife Service issued destruction guidance rather than a rinse instruction. Efforts to halt sales and pull stock succeeded, and to the best of the agencies’ knowledge no introduction into a waterbody resulted.
How do you safely destroy a contaminated moss ball?
The US Fish and Wildlife Service gives three methods. Freeze: place the moss ball into a sealable plastic bag and freeze for at least 24 hours. Boil: place the moss ball in boiling water for at least 1 full minute. Bleach or vinegar: submerge in unscented bleach diluted to one third cup per gallon for 10 minutes, or undiluted white vinegar for 20 minutes. Then dispose of the moss ball and any of its packaging in a sealed plastic bag in the trash and never down a drain, into a waterway or onto a garden. All three methods kill the ball, which is the intent.
What eats moss balls?
Aquarium Store Depot says to avoid pairing with plecos, crayfish, and cautiously with goldfish and cichlids. Aquarium Care Basics names one: goldfish may be interested in it as a food source. On our own records that is our goldfish, common pleco and bristlenose pleco records, and crayfish has none here. Shrimp and snails are cleared: Aquarium Care Basics says they feed on trapped food particles rather than consuming the moss ball itself.
How long do moss balls live?
The sources disagree by an order of magnitude, which is why this record has no lifespan row. Aquarium Breeder: 50 to 100 years in the wild and up to 10 years in a tank set-up if properly cared for. Aquarium Store Depot: the oldest known marimo ball is about 200 years old, with the actual maximum unknown. Wikipedia publishes no figure. Ten years and two hundred are not the same claim.
Do moss balls help clean the water?
Barely, and the source that makes the claim also withdraws most of it. Aquarium Breeder lists nitrate reduction as a small bonus and gives the reason: they grow very slowly. As a result, their consumption rate is also pretty low. On outcompeting nuisance algae it says the effect is mostly possible in smaller tank set-ups. What it does claim without hedging is that Marimo Moss balls do not produce any waste in the tank, unlike other plants that do shed their leaves, and that the structure harbors a good amount of beneficial bacteria.
Are marimo moss balls good for shrimp?
Yes, and this is the function that survives scrutiny. Aquarium Breeder: marimo moss balls serves as grazing or foraging ground for inverts and small fish. Tiny bits of food get trapped in the algae filaments which the shrimp can graze on, which it links to better shrimplet survival. Aquarium Care Basics describes the same behavior from the other side, that shrimp and snails feed on trapped food particles rather than consuming the moss ball itself. It names Neocaridina, Caridina, amano, ghost, bamboo and vampire shrimp as compatible, and our cherry shrimp, amano shrimp and ghost shrimp records all contain this record’s pH of 7.0.
Do marimo moss balls oxygenate a tank?
One source says so in the ordinary way any photosynthesizing organism does. Aquarium Breeder: just like other aquatic plants, Marimo uses up CO2 and provides oxygen in the tank as a result of the photosynthesis process. No source we hold quantifies it, and the same source is explicit that the slow growth limits every other metabolic benefit it lists, so this is best read as true and small.
Are moss balls protected or endangered?
Protected in two countries. Wikipedia: the marimo has been a protected species in Japan since the 1920s, and in Iceland since 2006. What no source we hold states is where shop stock actually comes from, so this record cannot tell you whether a given ball is cultivated or collected. Given the growth rate of five millimeters a year, that is a question worth asking a retailer.
What a moss ball needs that a java fern does not
One of these is a quarantine step that a government agency wrote.
- A sealed bag and a freezer, before the tankthe US Fish and Wildlife Service response to the 2021 zebra mussel finding gives freezing in a sealable plastic bag for at least 24 hours as one of three approved methods, and station 05 has the other two
- Your hand, once a weekWikipedia notes the round shape is maintained by gentle wave action that occasionally turns it, and a tank has no waves, so turning and squeezing the ball is the whole of its maintenance
- Shade, or a spot out of the beamtwo of three sources say direct intense light produces brown patches, and Wikipedia places the wild form on the shaded sides of rocks at the bottom of lakes
Every item our records ask for is gathered on the tank setup topic.
Nothing here is a paid link. It is the shortfall between what this record asks for and what a boxed kit contains.
How this record was compiled
- By
- Verified
- Sources
Wikipedia, Aegagropila linnaei, US Fish and Wildlife Service, invasive zebra mussels found in moss balls, Aquarium Store Depot, marimo moss ball care, Aquarium Breeder, marimo moss ball care guide and Aquarium Care Basics, marimo moss ball
- Conflicts
Printed rather than resolved: four sources give four versions of the scientific name and one still uses the genus retired in 2002; the two sources that publish a pH range overlap at exactly one value, 7.0; one source gives a temperature floor of 43 °F against 65 and 72 from the other two; and two sources say to keep it out of intense light where a third gives low to high.
- Not recorded
A hardness row, because the plant schema on this site does not carry one; a lifespan in a row, because the sources disagree by an order of magnitude between up to 10 years in a tank and 50 to 100 in the wild, with one noting the oldest known ball is about 200 years old; a light figure in PAR, because no source publishes one; and whether any individual ball for sale is wild collected, because the species is protected in Japan since the 1920s and in Iceland since 2006 and no source we hold says where shop stock comes from