The first plant record here, and it has no roots
The plants silo published its schema before it had a single record in it, and said why: fish records answer whether an animal fits and who it can live with, and plant records answer will it grow in my tank, which is a different question with different fields. This is the first record written to that schema.
Hornwort is the right plant to start with for two reasons that have nothing to do with it being the most searched. The first is the field most people get wrong: it has no roots. Wikipedia describes a submerged, free floating aquatic plant, Splashy Fish gives the mechanism, that it lacks true roots and absorbs nutrients directly from the water column, and Aquarium Breeder gives the consequence in capitals: do not try to root hornwort in the substrate, the buried part will start decaying.
The second is that two of our own records already name it, and a third carries the problem it might solve. Our oscar record carries Aquarium Source recommending hornwort as a floating plant precisely because the digging an oscar does will not damage it. Our ember tetra record names it too. And our goldfish record carries the problem this plant might solve: because goldfish eat live plants, their presence in a planted aquarium can be problematic.
Might, because our sources will not settle it. Aquarium Co-Op states that plant eating animals such as goldfish, koi, African cichlids and turtles do not eat hornwort. Aquarium Breeder states that you should avoid keeping the plant with gouramis, oscars, goldfish and herbivorous cichlids. Station 07 prints both.
Why this record was written now
- The gap
- The plants silo held nothing at all against fourteen names in its queue, on a site where three records already cite a plant their own sources named and we could not describe.
- What it changes
- The record page now carries two schemas rather than one: nine animal fields or nine plant fields, chosen by silo. Everything else on the site, every count and every token, still means the animal set.
- What it does not
- Two fields have no figure. There is no tank size, because a floating plant does not have one, and no light figure in lumens, because the only source that publishes a number gives PAR and PAR is the right unit.
Do not plant it. That is the whole instruction
The silo's schema calls substrate the field that decides whether a plant can go in the tank you already have. On this record it decides something simpler: whether the plant survives the first week.
- Wikipedia. A submerged, free floating aquatic plant. It lacks roots entirely, and it overwinters in the wild by forming turions: buds that sink to the bottom of the water and stay there during the winter before forming new plants in spring.
- Splashy Fish. It lacks true roots and instead absorbs nutrients directly from the water column. That is why the fertilizer advice on this record is liquid rather than a root tab.
- Aquarium Co-Op. Because it never grows proper roots, the attached end tends to rot away. It says hornwort grows best as a floating plant.
- Aquarium Breeder. Do not try to root hornwort in the substrate. It will not end well. The buried part will start decaying. Weigh it down with something else, or use suction cups.
- Aquarium Source. The one source that describes planting it as a normal thing to do, and even it does not bury the stem: take suction cups and pin the base of the stem to the bottom.
So the row reads none, it has no roots, and the practical instruction is that a bunch of hornwort is either floating at the surface or pinned at the base by something that is not substrate. Every source that mentions burying it mentions rot in the same breath.
What you are looking at, if you are buying it from a photograph: Wikipedia describes stems reaching 1 to 3 m with leaves 8 to 40 mm long, and Aquarium Breeder gives the stem a diameter of about 2 mm. The leaves are the needles every source mentions shedding, arranged in whorls along a stem thin enough to cut with your fingers. Wikipedia also gives the one feature that separates it from soft hornwort, Ceratophyllum submersum, which it says is easily confused with it when the growth is young: the leaves of rigid hornwort are forked only once or twice, rather than three to four times.
This is the same failure the plants silo already warned about for a different reason. Anubias and java fern are epiphytes whose rhizome rots if it is buried, which the silo calls the main beginner mistake. Hornwort gets to the same outcome without a rhizome to bury: there is simply nothing down there to plant.
Light and CO2, the two fields that decide a beginner tank
The silo says CO2 is the single field that decides whether a plant belongs in a beginner tank, and that light is stated as a demand rather than a lumen figure because tank depth changes what a fixture delivers. Both hold up here, and one source published a number anyway, in the right unit.
| Source | Light | Hours a day | CO2 |
|---|---|---|---|
| Aquarium Co-Op | Low to high | Not stated | Not required |
| Aquarium Source | A small amount to survive | Not stated | Not stated |
| Splashy Fish | Medium to high, 30 to 50 PAR | 8 to 10 | Not required, faster and denser with it |
| Aquarium Breeder | Medium, not too weak or strong | 10 to 12 | Not compulsory, but it will help |
| Wikipedia | Not stated | Not stated | Not stated |
- The light row is a range of demands, not a range of numbers. Low light keeps hornwort alive and medium to high is where it grows, which is why the field reads the way it does. A reader who buys it for a dim tank has not been misled, they just will not get the dense green mass the photographs show.
- PAR is the exception that proves the silo's rule. Splashy Fish is the only source to publish a figure and it gives 30 to 50 PAR rather than lumens. PAR is measured at the plant, which is exactly the depth problem the schema names, so the one numeric source picked the one unit that survives it.
- The two photoperiods do not match. 8 to 10 hours at Splashy Fish, 10 to 12 at Aquarium Breeder, and neither explains its own. Both are inside what a timer does, so the disagreement costs a reader nothing, but it is printed rather than averaged.
- CO2 is optional on every source that mentions it. On the silo's three way vocabulary of required, beneficial or unnecessary, this is beneficial: two sources say what it buys, and it is faster growth on a plant whose problem is already that it grows too fast.
The full record
| Field | Recorded | Where it comes from |
|---|---|---|
| Light | Low to survive, medium to high to grow | Four sources and four ways of saying it, which is why this row is a demand rather than a figure. Aquarium Co-Op: it will grow under low to high light. Aquarium Source: it only needs a small amount of light intensity to survive. Splashy Fish is the only source to publish a number, medium to high at around 30 to 50 PAR for 8 to 10 hours a day. Aquarium Breeder asks for medium lighting, avoiding too weak or too strong, for about 10 to 12 hours a day. The two photoperiods do not match and neither source explains its own. |
| CO2 | Beneficial, never required | All three sources that mention CO2 agree it is optional, and two of them say what it buys. Aquarium Co-Op: it does not require carbon dioxide injection. Splashy Fish: it does not require CO2 injection, but will grow faster and denser if provided. Aquarium Breeder: the addition of CO2 is not compulsory but it will help. On the silo's own three way vocabulary of required, beneficial or unnecessary, this is beneficial. |
| Placement | Floating, or background if anchored | Aquarium Breeder gives both in one field: background or floating. Aquarium Co-Op says it grows best as a floating plant and that it is best used as a background plant in larger tanks. Wikipedia describes it as often used as a floating freshwater plant in both coldwater and tropical aquaria. Nothing here belongs in the foreground, and the reason is in the next row. |
| Substrate | None. It has no roots | This is the field to read before buying it, and four sources say the same thing in four registers. Wikipedia states plainly that it is a submerged, free floating aquatic plant, and Splashy Fish gives the mechanism: it lacks true roots and instead absorbs nutrients directly from the water column. Aquarium Co-Op explains what follows: because it never grows proper roots, the attached end tends to rot away. Aquarium Breeder is the blunt one: do not try to root hornwort in the substrate, it will not end well, the buried part will start decaying. Both it and Aquarium Source give the same workaround, weighing the stem down or pinning the base with suction cups. |
| Growth rate | 1 to 4 in a week | Aquarium Co-Op, which states it will easily grow 1 to 4 inches, 3 to 10 cm, per week. Aquarium Breeder gives a faster figure in a different unit: 1 to 2 cm a day, which is 2.8 to 5.6 inches a week, and calls the rate moderate to high. Both agree on the consequence, which every source repeats: it needs trimming regularly or it takes the tank. Aquarium Breeder adds that you can cut it into two or three parts and it will still survive. The other end of this silo makes the figure easier to feel. Our marimo moss ball record publishes 5 mm a year on three sources, about an inch every five years, so at the slow end of this row hornwort grows in seven days roughly five times what that alga grows in a twelvemonth. The two are in the same silo, neither needs CO2, and both tolerate water below 60 °F. |
| Propagation | Cuttings. Any segment regrows | Aquarium Co-Op: cut off a side shoot or trim off the top of a tall stem, and any segment of hornwort will quickly become a new plant if you let it float at the surface or plant it in the ground. Splashy Fish puts a length on it, a healthy section of about 4 to 6 inches. Aquarium Breeder: cut off the stems and let them float on the water surface. Wikipedia records that it is propagated by cuttings, and adds the wild version of the same trick: it forms turions, buds that sink to the bottom over winter before forming new plants in spring. |
| Temperature | 59 to 86 °F | Aquarium Source and Splashy Fish publish this band identically. The other two are close and neither matches: Aquarium Co-Op gives around 50 to 85, which is the only figure on this site with a floor in the fifties, and Aquarium Breeder gives 64 to 86 with 75 to 79 as optimal. All four bands contain 64 to 85. Wikipedia explains the wide floor without giving a number, describing a plant used in both coldwater and tropical aquaria. |
| pH | 6.0 to 7.5 | Aquarium Source and Splashy Fish again publish the same band, and Splashy Fish adds that slightly acidic to neutral water supports the best growth. Aquarium Breeder is wider, calling 6.0 to 8.0 optimal, and adds the figure that puts the whole row in perspective: in nature hornwort tolerates pH from 6.5 to 10.2. On hardness, Aquarium Source and Splashy Fish both give 5 to 15 dGH and Aquarium Breeder gives 3 to 17. |
| Eaten by | Not goldfish, according to one source and against another | The sharpest disagreement on this record, and it is about two animals we hold records for. Aquarium Co-Op states that plant eating animals such as goldfish, koi, African cichlids and turtles do not eat hornwort. Aquarium Breeder states the opposite list: avoid keeping the plant with gouramis, oscars, goldfish and herbivorous cichlids, because these fish species can damage the plant. Splashy Fish adds that betta fish typically do not eat hornwort, and Aquarium Source adds that certain species like gouramis will probably eat it, which is the one point those two sources agree on. Aquarium Source also names it as the plant for a tank of livebearers, because guppies, mollies, Endler's livebearers and platy fish will likely use it as a place for fry. |
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 the first plant record it is not about water at all: two sources give opposite answers to the question a keeper with fish actually asks.
Aquarium Co-Op
Plant-eating animals (such as goldfish, koi, African cichlids, and turtles) do not eat hornwort.
Aquarium Breeder
Avoid keeping the plant with Gouramis, Oscars, Goldfish, and herbivorous cichlids. These fish species can damage the plant.
What we record: we carry neither as a verdict and print both, because the two lists overlap on goldfish and on cichlids and cannot both be right. What can be said is narrower and more useful: eating a plant and damaging a plant are not the same claim, and only one of these sources uses the word eat.
A fish that uproots or shreds a floating stem has damaged it without having eaten it, which is exactly the distinction our oscar record turns on, where Aquarium Source recommends hornwort for an oscar tank precisely because the digging will not hurt it. Three sources describe an animal problem for this plant and no two of them name the same animals.
The growth rate is the reason to buy it and the reason to regret it
Two figures, two units
Aquarium Co-Op states hornwort will easily grow 1 to 4 inches, 3 to 10 cm, per week. Aquarium Breeder gives 1 to 2 cm a day, which works out at 2.8 to 5.6 inches a week, and calls the rate moderate to high. This record carries the slower published figure and prints the faster one.
Either way the consequence is the one every source repeats, and the silo's schema predicted it: growth rate is the field that turns a plant from an asset into a chore. Aquarium Source says you will need to clip or prune the stems from time to time. Aquarium Breeder says it tends to grow like crazy and will overstuff the tank.
The upside is in the same figure. A plant growing an inch or more a week is taking nutrients out of the water at that rate, which is why Splashy Fish describes it absorbing excess nitrates, phosphates and ammonia, and Aquarium Co-Op calls fast growing plants like hornwort good at cleaning aquarium water because they consume waste compounds.
And it fights algae chemically
Two independent sources describe something no other plant claim on this site can match. Aquarium Breeder states that hornwort has allelopathic qualities, excreting substances that inhibit the growth of blue green algae and phytoplankton. Wikipedia says the same thing in its own words: it excretes substances that inhibit the growth of phytoplankton and cyanobacteria.
Blue green algae and cyanobacteria are the same thing, so this is a reference source and a hobby source agreeing on a mechanism rather than on a number, which is rarer here than it sounds.
Set against our water and health topic, that puts hornwort on both sides of the nitrogen question: it consumes the compounds the topic is about, and it suppresses one of the organisms that appears when they accumulate.
Propagation is cutting it in half
The silo's schema asks how a plant multiplies: runners, cuttings, rhizome division or plantlets on the leaf edge. This one is cuttings, and every source says so in almost the same words.
- Aquarium Co-Op. Cut off a side shoot or trim off the top of a tall stem. Any segment of hornwort will quickly become a new plant if you let it float at the surface or plant it in the ground.
- Splashy Fish. Trim a healthy section of the stem about 4 to 6 inches long. Each fragment will continue growing.
- Aquarium Breeder. Cut off the stems and let them float on the water surface. You can cut it into 2 or 3 parts and hornwort will still survive.
- Wikipedia. Propagated by cuttings, and it does the same thing on its own in the wild: turions, buds that sink to the bottom over winter before forming new plants in spring.
- What that means for the trimming problem. The maintenance job and the propagation method are the same action. Every cutting you take to stop it overstuffing the tank is a new plant, which is why nobody buys hornwort twice.
The same trait is why it is a weed. Wikipedia records it as a harmful weed introduced in New Zealand and a declared weed under the Tasmanian Weed Management Act 1999 in Australia, and Aquarium Breeder notes it has been declared an invasive species because it can spread and disperse easily. Trimmings go in the bin, not in a waterway. Our ghost shrimp and oscar records carry the same note about animals; this is the first plant on the site to carry it.
Eaten by: two sources, opposite answers
The silo's schema says this field is cross linked both ways: which animals in our records will graze it or dig it up. On the first plant record the field is a contradiction, and it is a contradiction about two species we hold.
| Source | Names as a problem | Names as safe |
|---|---|---|
| Aquarium Co-Op | None | Goldfish, koi, African cichlids, turtles: they do not eat hornwort |
| Aquarium Breeder | Gouramis, oscars, goldfish, herbivorous cichlids: they can damage the plant | All shrimp and snail species |
| Aquarium Source | Gouramis will probably eat it | Compatible with all kinds of fish; livebearers use it for fry |
| Splashy Fish | None | Betta fish typically do not eat hornwort |
| Wikipedia | Not addressed | Not addressed |
- Goldfish appear on both lists. One source says they do not eat it, another says keep them apart. Our goldfish record carries Wikipedia stating that goldfish eat live plants, which makes this the first plant here that might have answered that record's open problem. It does not.
- Eating and damaging are different claims. Only Aquarium Co-Op uses the word eat, and only Aquarium Breeder uses the word damage. A fish that shreds or uproots a floating stem has damaged the plant without eating it, and on a rootless plant that drifts, damage is the easier of the two to do.
- Which is exactly what our oscar record turns on. There, Aquarium Source recommends hornwort for an oscar tank because the digging will not hurt it, and Aquarium Breeder names oscars among the fish to keep away from it. The oscar record now says so.
- Gouramis are the one thing two sources agree on. Aquarium Source says gouramis will probably eat it and Aquarium Breeder says to avoid them. The honey gourami is in our fish queue, so this site will hold the animal side of that pairing before long.
- Invertebrates are safe on every source that mentions them. Aquarium Breeder lists all shrimp varieties and snail species as compatible. Our cherry shrimp, amano shrimp, ghost shrimp and nerite snail records are all inside that.
The water, and a band as wide as anything here
Temperature
59 to 86 °F, which Aquarium Source and Splashy Fish publish identically. Aquarium Breeder gives 64 to 86 with 75 to 79 as optimal. Aquarium Co-Op is the outlier and the interesting one: around 50 to 85, and that floor is the lowest temperature figure anywhere on this site.
Wikipedia explains the width without giving a number, describing a plant often used as a floating freshwater plant in both coldwater and tropical aquaria. A plant that works in both is a plant with a band no animal record here needs.
The practical value is the one thing the silo said temperature was for: a planted community can be checked for overlap in one pass. The carried band contains every animal temperature range on this site, including the goldfish at 68 to 74 and the angelfish at 78 to 84, which cannot share water with each other. It is exactly as wide as our cherry shrimp record, which carries the same 59 to 86, so it is joint widest rather than widest.
pH and hardness
pH 6.0 to 7.5, published identically by Aquarium Source and Splashy Fish, with the latter adding that slightly acidic to neutral water supports the best growth. Aquarium Breeder is wider at 6.0 to 8.0 optimal.
And then Aquarium Breeder gives the figure that puts the row in perspective: in nature, hornwort tolerates pH from 6.5 to 10.2. Nothing else on this site has a published tolerance that reaches ten.
Hardness is 5 to 15 dGH at both Aquarium Source and Splashy Fish, and 3 to 17 at Aquarium Breeder. Converted at about 17.9 ppm per degree that is roughly 54 to 304 ppm, which sits in the middle of what our animal records ask for rather than covering them: those run from 0 ppm on the kuhli loach floor to 536 on the guppy ceiling. Our water and health topic holds them all in one place.
What this record will not answer
Four things our five sources do not settle.
- Whether goldfish will eat it. Two sources, opposite answers, printed in station 07. This is the field a keeper most wants and the one we cannot close.
- What size tank it needs. Only Aquarium Source offers a figure, around 15 gallons as a general rule with 10 gallon tanks possible given frequent pruning, and a floating plant does not really have a minimum. The plant schema has no tank field for that reason.
- How much light in lumens. Nothing, and deliberately. The only numeric source gives 30 to 50 PAR, which is the unit measured at the plant rather than at the fixture, and converting it would invent a figure nobody published.
- How long it lives. No source states a lifespan for a plant that is propagated by cutting it in half, and it is not obvious the question means anything. There is no lifespan field on the plant schema.
Hornwort questions, answered from the record
How to plant hornwort in an aquarium
You do not, and this is the most repeated mistake about the plant. Aquarium Breeder states it plainly: do not try to root hornwort in the substrate, it will not end well, the buried part will start decaying. Aquarium Co-Op explains why, that because it never grows proper roots the attached end tends to rot away.
The two options our sources give are floating, which Aquarium Co-Op says it does best, or anchoring the base without burying it. Aquarium Source pins the stem with suction cups and Aquarium Breeder weighs it down. Wikipedia describes the plant as free floating and rootless, which is the reason behind all of it.
How to anchor hornwort when it has no roots
Suction cups at the base, per Aquarium Source, or a weight, per Aquarium Breeder. Neither buries the stem. That is the whole trick: the plant is held in place mechanically rather than rooted, so the part in contact with the substrate is as short as possible.
If it is going to float instead, Aquarium Co-Op says it is best used as a background plant in larger tanks, and Aquarium Source notes that livebearers such as guppies, mollies, Endler's livebearers and platy fish will likely use a floating mass as a place for fry.
How to grow hornwort faster, and how fast it grows already
1 to 4 inches a week, which is 3 to 10 cm, from Aquarium Co-Op. Aquarium Breeder gives a faster figure in a different unit, 1 to 2 cm a day, which comes out at 2.8 to 5.6 inches a week. This record carries the slower published figure.
In the wild it goes much further. Wikipedia gives stems of 1 to 3 m, 3 to 10 ft, and Aquarium Source says it can grow up to ten feet in length. Aquarium Breeder gives the same range and a stem diameter of about 2 mm.
Do goldfish eat hornwort?
Our sources contradict each other, so this record does not answer it. Aquarium Co-Op states that plant eating animals such as goldfish, koi, African cichlids and turtles do not eat hornwort. Aquarium Breeder states the opposite, that you should avoid keeping the plant with gouramis, oscars, goldfish and herbivorous cichlids because these fish species can damage the plant.
The distinction worth holding on to is that only one of them uses the word eat. Damaging a rootless floating plant and eating it are different actions. Station 07 prints every statement from all five sources.
Does hornwort need CO2?
No, on all three sources that mention it. Aquarium Co-Op says it does not require carbon dioxide injection. Splashy Fish says it does not require CO2 but will grow faster and denser if provided. Aquarium Breeder says the addition is not compulsory but will help.
On the plant schema's three way vocabulary of required, beneficial or unnecessary, that makes it beneficial. Worth noting what the benefit is on this particular plant: faster growth, on a plant whose only real problem is how fast it already grows.
How much light does hornwort need?
Low light keeps it alive and medium to high is where it grows. Aquarium Co-Op says it will grow under low to high light, Aquarium Source says it only needs a small amount of light intensity to survive, and Aquarium Breeder asks for medium lighting, avoiding too weak or too strong.
Splashy Fish is the only source with a number and it is in the right unit: medium to high at around 30 to 50 PAR, for 8 to 10 hours a day. Aquarium Breeder asks for 10 to 12 hours instead, and neither explains its own photoperiod.
What water parameters does hornwort need?
Temperature 59 to 86 °F and pH 6.0 to 7.5, both published identically by Aquarium Source and Splashy Fish. Hardness is 5 to 15 dGH from the same two sources, with Aquarium Breeder giving 3 to 17.
The band is the widest on this site, and Aquarium Breeder adds the figure that shows why: in nature hornwort tolerates pH from 6.5 to 10.2. Wikipedia gives the aquarium version of the same point, describing a plant used in both coldwater and tropical tanks. Aquarium Co-Op's temperature floor of about 50 °F is the lowest figure anywhere on this site.
How do you propagate hornwort?
Cut it. Aquarium Co-Op: cut off a side shoot or trim the top of a tall stem, and any segment will quickly become a new plant. Splashy Fish puts a length on it, a healthy section of about 4 to 6 inches. Aquarium Breeder says you can cut it into two or three parts and it will still survive.
The maintenance job and the propagation method are the same action, which is the useful thing to know: the trimming you have to do anyway produces the new plants.
Why is my hornwort shedding needles?
Because something changed. Aquarium Co-Op gives the fullest answer: hornwort sheds needles any time there is a major change in water parameters, or it is kept in an unfavorable environment such as strong currents, not enough light, lack of nutrients, or dosing of certain chemicals.
Splashy Fish names sudden temperature swings and nutrient deficiencies. Aquarium Source says it might shed a little from time to time and to check for poor water conditions or lighting that is not ideal if it is excessive. All three treat shedding as a symptom of change rather than of the plant being wrong.
Does hornwort help with algae?
Two ways, and one of them is chemical. The first is competition: Splashy Fish describes it absorbing excess nutrients such as nitrates, phosphates and ammonia, and Aquarium Co-Op calls fast growing plants like hornwort good at cleaning aquarium water because they consume waste compounds.
The second is allelopathy, and two independent sources describe it. Aquarium Breeder says hornwort excretes substances that inhibit the growth of blue green algae and phytoplankton, and Wikipedia says it excretes substances that inhibit the growth of phytoplankton and cyanobacteria. Blue green algae and cyanobacteria are the same thing.
Can hornwort grow floating?
It grows best that way, according to Aquarium Co-Op, and Wikipedia describes it as often used as a floating freshwater plant. Aquarium Breeder lists its placement as background or floating, and its propagation method is to cut stems and let them float on the surface.
Floating changes what the plant is for rather than whether it works: a floating mass shades the tank and gives fry cover, which is the use Aquarium Source describes for a livebearer tank, while an anchored stand at the back is a background plant.
Is hornwort invasive?
Yes, in places, and the sources are specific. Wikipedia records it as a harmful weed introduced in New Zealand and a declared weed under the Tasmanian Weed Management Act 1999 in Australia. Aquarium Breeder says it has been declared an invasive species in recent times because it can spread and disperse easily.
Which is the same trait that makes it easy to propagate. Any segment becomes a new plant, so trimmings belong in the bin rather than in a waterway.
Where does this record differ from the animal records here?
It carries a different nine fields, and that is the point. Light, CO2, placement, substrate, growth rate, propagation, temperature, pH and eaten by, instead of minimum tank, temperature, pH, hardness, adult size, diet, water column, lifespan and growth rate. The plants silo published that schema before it had a record to put in it.
It also does not appear in the stocking calculator or in any tank mate grid, because a plant has no minimum tank and no temperament. The full index lists every record we hold and the method page explains what happens here when two sources disagree.
What hornwort needs and a rooted plant does not
Three things our sources ask for, and none of them is substrate.
- Something to weigh it down, or nothing at allsuction cups, or let it float
- Scissors, on a schedule1 to 4 inches a week
- Liquid fertilizer, because it feeds from the waternitrogen and iron
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
Aquarium Co-Op, hornwort care, Aquarium Source, Splashy Fish, Aquarium Breeder and Wikipedia, Ceratophyllum demersum
- Conflicts
Printed above: two sources give opposite answers about goldfish and cichlids
- Not recorded
A tank size, because a floating plant does not have one and only one source offered a figure, and a light figure in lumens, because the one numeric source gives PAR instead and PAR is the right unit