The care record
Four records are written in this silo and 3 are queued below. Everything on this page comes from those records or from the sources named on them. The four do not get on at all: our assassin snail record carries a source saying it eats mystery and nerite snails eventually, three sources naming ramshorn snails as prey, and one naming rabbit snails, so one of the four records here refuses the other three.
Every field, including the blanks
The full record, in the same nine fields every species on this site carries. Two of them are empty and the record says which sources were checked and what they gave instead.
| Field | Nerite snail | Ramshorn snail | Assassin snail | Rabbit snail |
|---|---|---|---|---|
| Minimum tank | 2 to 3 gal | 5 gal | 10 gal | 10 gal |
| Temperature | 72 to 79 °F | 70 to 78 °F | 75 to 80 °F | 78 to 84 °F |
| pH | 7.5 to 8.5 | 7.0 to 7.5 | 7.0 to 7.5 | 7.5 |
| Hardness | 215 to 322 ppm | 143 to 322 ppm | 107 to 268 ppm | 107 to 143 ppm |
| Adult size | 0.5 to 1.5 in (13 to 38 mm) | 0.7 to 1 in (18 to 25 mm) | 1 to 1.2 in (25 to 30 mm) | 2 to 4 in (5 to 10 cm) |
| Diet | Algae, leftover food, decaying leaves | Algae and detritus, and live plants when the rest runs out | Carnivore. It hunts snails and does not eat algae | Algae and detritus, and it eats java fern |
| Water column | Substrate, and every surface above it | Every surface, and it breathes air | Substrate, and buried in it | Substrate, and tunnels through it |
| Lifespan | 1 to 2 years | 1 to 2 years | 2 to 5 years | 2 to 3 years |
| Growth rate | not recorded | not recorded | not recorded | About a year to 1.5 in |
Hardness is the blank that matters. A shell is built from minerals taken from the water, so this is the field the animal is made of, and no source we are willing to name publishes a range for it. What Aquarium Co-Op gives instead is the symptom, cracked or eroded shells in soft tap water, and the remedy, crushed coral or a mineral supplement.
Three things the record settles
The eggs will not hatch
Four sources agree. Shrimp Science states the young require a brief period of brackish conditions; Aquarium Co-Op states the eggs need brackish or salt water; Wikipedia describes an animal that returns to brackish water to breed.
Minerals, or the shell goes
Aquarium Co-Op attributes cracked and eroded shells to soft tap water and names crushed coral or a mineral supplement as the fix. It asked for a pH above 7.0 with no ceiling, and two later sources closed it: the field now reads 7.5 to 8.5, the overlap of the three that state a figure.
A lid, because they leave
They move to the waterline to eat the mineral bands evaporation leaves there, and may keep going. The stated answer is a tight fitting lid with every snail sized hole covered.
Why the other snails are a different question
The three names queued below are not three more versions of these records. They breed in the tank, and that changes what a care page has to tell you: not how to keep one alive, but what happens when there are forty.
What our source says about them
Shrimp Science covers several. Bladder snails require a mate to reproduce. Ramshorn snails are hermaphroditic, with both sets of organs, and still need another snail to breed. Pond snails breed asexually and very quickly. And of the Malaysian trumpet snail it says you will almost certainly start to see baby snails on the glass within a few weeks.
That is four different reproductive arrangements in one paragraph, which is why they cannot share a page. It is also the whole of what we hold on any of them: no tank size, no temperature, no pH, no size.
What we will not do in the meantime
Publish a verdict. An earlier version of this page said one of these snails cleared a betta tank and another was risky, on the strength of a behavior nobody we could name had published. Those verdicts have been removed, and the removal is recorded on the method page.
The pattern is worth naming because it is the easiest mistake to make here. A plausible sentence about an animal is not a record, and a page full of them reads better than this one and is worth less.
Questions about freshwater aquarium snail care
Which aquarium snail will not overrun my tank?
The nerite, and on our records it is the only one. Its young need brackish water, so the eggs it leaves in a freshwater tank never hatch. Every other snail our source covers reproduces in the tank one way or another.
What are the hard white specks on my glass and wood?
Nerite eggs, if they are hard, white and about the size of a sesame seed. Aquarium Co-Op describes them exactly that way, laid on driftwood and in the substrate, each containing dozens of eggs, and difficult to remove. They will not hatch.
How small a tank can a snail go in?
Two to three gallons for the nerite, which is the smallest minimum on this site. That figure is the reason this silo matters out of proportion to its size: it is the only animal we hold a record on that suits a tank most keepers already regret buying.
Why is my snail's shell pitted or cracking?
Soft tap water, per Aquarium Co-Op, which names crushed coral and mineral supplements as the fix. We cannot tell you the hardness to aim at because no source we name publishes one, and the record leaves that field blank rather than guessing.
Do snails need a lid?
The nerite record asks for one, and it is the only equipment requirement on the page. The reason is specific: it climbs to the waterline to eat the mineral bands evaporation leaves, and may carry on over the rim.
Are snails safe with shrimp?
Yes, and it is the pairing our one substrate exception was written for: both are grazers and our sources describe them as company rather than as alternatives. Set the water by the shrimp record, because it publishes a hardness figure and this one does not.
Will a snail eat my plants?
Shrimp Science states that nerite snails will only eat the decaying parts of a plant. For the other snails in the queue we hold nothing on this at all, which is a real gap: it is one of the first things anybody asks.
How many snails do I need for an algae problem?
No source we hold states a number, so this site does not give one. What the record does say is the other half of the question: a snail bought to eat a surplus needs the surplus to exist, and when the algae goes the animal has to be fed.
Why are there only four records here?
Because the sources behind our fish records do not cover invertebrates, and finding sources that do is what holds this silo up. The three queued names are waiting on the same thing rather than on somebody finding time to write them. The four written are as different as the silo gets: the nerite grazes algae, the assassin is a carnivore that will not touch algae, and the ramshorn is the one that arrives on a plant without being bought.
Where do nerite snails come from?
Wikipedia gives East Africa for Vittina natalensis, from Kenya to South Africa, and lists the species as Near Threatened. It also states the animal can only reproduce in brackish or salt water. How the ones in the shops are produced is not something any of our sources says, and the record does not guess.
What is not here yet
Three snail records in the queue
None of these is written. Each one needs a source that states its fields rather than a paragraph describing its behavior, and for four of the five the only thing we currently hold is how they reproduce.
Who eats a snail, and who a source says will not
Compatibility on this site is usually read out of silences: a source describes an animal, says nothing about a second one, and the grid stays empty. On aquarium snails one source is direct, and four of the species it names are records we already hold.
AquaticMotiv names loaches, pufferfish and larger cichlids as tank mates to avoid, on the grounds that they may nip or eat snails. Read against our own records, one of the three holds up, one is already our own refusal, and one is contradicted by a source about the specific animal. It names tetras, guppies, cory catfish and rasboras as safe companions, and states that snails are safe with freshwater shrimp.
- The pea puffer is the pufferfish. Our record already files snails as its diet rather than its company, so this is a source agreeing with a refusal we had derived.
- We hold two loaches and they answer the warning in opposite directions. AquaticMotiv warns about loaches as a group. Aquarium Co-Op says of the kuhli loach, in as many words, that it is not known for eating snails, and that record carries the sentence as both an answer and a warning against buying the fish for pest control. Then the clown loach record arrives with four of its five sources naming snails as food, Aquarium Source saying it will eat any freshwater snail it can get ahold of, and our nerite snail record refused against it. So the group warning was right about one loach and wrong about the other, which is the argument for a species record rather than a family rule, stated by the family rule getting it half right.
- Four cichlid records are written here now, the oscar, the angelfish, the discus and the flowerhorn, which is a hybrid of cichlids rather than a species. Three of the four say nothing at all about snails. The fourth is the one that matches the warning: Everything Fishkeeping names snails among the animals to keep away from a flowerhorn, alongside shrimp, tetras, bettas, goldfish, angelfish and rasboras. So the larger cichlids half of the warning is now one for one on this site, and two dwarf rams are still queued.
- On the safe side we hold three of four: the ember tetra, the guppy and the corydoras catfish. The fourth is written too now: our chili rasbora record is the rasbora, and nothing on it or on the nerite snail record puts the two in conflict, so the source is four for four.
Algae is the reason, and it is not all algae
Nobody buys an aquarium snail for its personality. Every source in this silo leads with algae except the ones on the second record, and the nerite record is specific about which algae in a way the group guides are not: soft green algae and brown diatoms, and not black beard and not green spot. Our assassin snail record is the exception that proves the sentence: Aquarium Breeder says twice that assassin snails do not eat algae, so the silo holds one snail bought for algae, one bought for snails, and one that eats algae and arrives without being bought at all.
That distinction is the difference between a snail that helps and a snail that starves in a tank full of algae. An established outbreak is usually the kind these animals do not eat, which is why a snail bought as a treatment arrives to a plate of the wrong food.
- What they graze is the film: soft green algae, brown diatoms, biofilm and decaying plant matter, on every source we hold.
- What they do not clear is a mature outbreak of the tough algae, and no source we have read claims otherwise.
- What to add when the tank runs out. AquaticMotiv gives algae wafers or blanched zucchini, spinach and cucumber, three to four times weekly, and says to remove uneaten food after 12 to 24 hours.
- Which is the same instruction the shrimp silo carries, for the same reason: in a small tank the uneaten food is the failure, not the hungry animal. The shrimp silo and this one compete for the same film, which the otocinclus record spells out.
The queue contains a food chain
Read the queue on this page as a list and it is five aquarium snails. Read it against the sources and it is not a list, it is a relationship. AquaticMotiv states that assassin snails prey on pest snails like bladder and ramshorn species, and Aquarium Source states that the main item on the menu for assassin snails is other snails and that they will happily eat a lot of the others.
Assassin, bladder and ramshorn are all three queued here. So one of the records this silo has not written yet is the reason two of the others get bought at all, and the order they are written in will have to say so.
The one already answered
Aquarium Source adds that trumpet snails can quickly reproduce and take over a tank if left unchecked, which is the whole distinction our nerite record is built on. AquaticMotiv states the other half in the same words we do: nerite snails do not reproduce in fresh water, so there is no overpopulation risk. Mystery snails, it says, lay pink egg clusters above the waterline, which can be removed by hand.
That is three of the five queued animals whose reproduction is already the deciding field, before a single record for them exists.
| Field | AquaticMotiv, for snails generally | The nerite record | The assassin snail record | The ramshorn record |
|---|---|---|---|---|
| Minimum tank | 5 to 10 gal | 2 to 3 gal | 10 gal | 5 gal |
| Temperature | 72 to 80 °F | 72 to 79 °F | 75 to 80 °F | 70 to 78 °F |
| pH | 7.2 to 8.0 | 7.5 to 8.5 | 7.0 to 7.5 | 7.0 to 7.5 |
| Hardness | 6 to 12 dGH | 12 to 18 dGH | 6 to 15 dGH | 8 to 18 dGH |
| Alkalinity | 4 to 8 dKH | 12 to 18 dKH | 2 to 10 dKH | 5 to 15 dKH |
| Lifespan | 1 to 3 years | 1 to 2 years | 2 to 5 years | 1 to 2 years |
| Copper | toxic to all invertebrates | lethal in trace amounts | sensitive to copper-based medications | fatal, and one source recommends it as a removal method |
Read the hardness row and the pattern from the fish silo repeats: the group figure and the nerite figure meet at 12 and share nothing else. A guide writing about aquarium snails as a group gives 6 to 12 dGH; the source that writes about the nerite gives 12 to 18; the assassin snail sources give 6 to 15, which is the only one of the three that contains the group figure it is supposed to belong to, and the ramshorn source gives 8 to 18.
The copper row is the one to read twice now: three of the four columns treat copper as a hazard and the fourth carries a source recommending it as a way to remove the animal, which our ramshorn record prints as its dispute. Both are printed and neither is averaged, and the practical reading is the one both of them agree on: whatever the number, a snail needs calcium out of the water, and soft acidic water is where shells erode.
AquaticMotiv names cuttlebone and calcium blocks; our record names crushed coral, Wonder Shells and Seachem Equilibrium.
Guides that start here
A guide is what this site writes when the question is not a species. The first one on this silo is about feeding, because the record on this page carries a source saying the animal can starve in a clean tank.