First, which snail
What to feed a snail has two completely different answers depending on whether the snail lives in water or on land, and this guide is about the one in your aquarium. If you are looking after a garden or pet land snail, nothing here applies: those animals are fed on a dish out of water, and this site holds no verified sources on them.
For an aquarium snail the question underneath the question is different again, and it decides everything else: does the tank already feed it? Our sources describe these animals as scavengers rather than as pets with a bowl. Aquarium Co-Op on the nerite: as scavengers, they dine on anything they can find, including algae, leftover fish food, and decaying leaves. On the mystery snail: their diet in an aquarium usually consists of fish food, algae, biofilm, dead fish, and dead plants, and as scavengers, they are not picky eaters and will eat way more than you think is possible.
Aquarium Care Basics lists the same larder from the tank's side: soft filmy algae that accumulate on slow growing plant leaves, aquarium glass and other hard surfaces, and shed plant matter that accumulates on the tank bottom for snails to eat.
So a mature, planted, lightly stocked tank feeds a snail without you. Our stocking page is where the lightly stocked half of that gets decided. A new tank, a bare tank, or a tank with fish that eat everything first does not, and station 02 is about what happens then.
What this guide is
- Scope
- Freshwater aquarium snails: nerite, mystery and the scavengers that arrive with plants. Not land snails, and not marine.
- Sources
- Five, all of them already cited elsewhere on this site, and two of them are method pages rather than care sheets: one on blanching a vegetable and one on calcium.
- The blank
- Not one of the five publishes a feeding frequency. Two publish a rule for taking food back out instead, and station 06 prints both.
The clean tank is the dangerous one
The reason to feed an aquarium snail at all is stated most plainly by Aquarium Co-Op, and it is not about growth or color. Nerite snails can starve to death if there is not enough algae in the tank or other fish are outcompeting them for food.
Read that against what the same animal is sold for. Our nerite snail record carries Aquarium Co-Op naming it as one of the few animals that will eat green spot algae, which is exactly why people buy it: to remove the algae. A snail bought to clear a tank of algae is a snail whose food supply you are paying it to destroy. That is the whole tension in this guide, and it is the reason the answer is not simply nothing, the tank will feed it.
Two of our records make the same point from the other direction. The nerite record carries Shrimp Science stating the snail will only eat the decaying parts of a plant, and our amano shrimp record carries a source saying a well fed amano is not an algae eater. Every algae eater on this site comes with a note saying algae will not feed it.
The signs our sources give are about the shell rather than the body. Aquarium Co-Op: if you have soft tap water and notice your snails are getting cracked or eroded shells, increase the minerals in their water and food. Aquarium Care Basics: cracked, thin or excessively pitted shells can be signs of calcium deficiency, and periodic calcium supplements may be necessary. Station 04 is about that, and our water and health page carries the hardness figures every record here publishes.
What to feed an aquarium snail, by source
Four of our five sources name foods. Nothing below is our suggestion: every item is on one of their pages.
| Food | Named for | Named by |
|---|---|---|
| Algae wafers | Nerite and mystery snails | Aquarium Co-Op, Aquarium Care Basics |
| Blanched zucchini | Nerite and mystery snails | Aquarium Co-Op, Aquarium Care Basics, Aquarium Breeder |
| Canned green beans | Nerite snails | Aquarium Co-Op |
| Blanched spinach or kale | Mystery snails, for shell minerals | Aquarium Co-Op |
| Leaf and iceberg lettuce | Mystery snails | Aquarium Care Basics |
| Bottom feeder tablets, pellets, fish flakes | Mystery snails | Aquarium Care Basics |
| Crab and shrimp foods | Mystery snails, one brand named | Aquarium Co-Op |
| Gel food mixed with calcium powder | Mystery snails | Aquarium Co-Op |
| Cucumber, carrot, broccoli, lima beans, cabbage | Snails, shrimp and fish generally | Aquarium Breeder |
Two things are absent from that table and both absences are deliberate. No source we hold names a fruit for a snail, and Aquarium Breeder says why it will not: I would not recommend to give shrimp any fruits, in general, they contain lots of sugar. And no source names a quantity. Every entry above is a food rather than a portion.
Aquarium Co-Op names one product for both snails and gives its reason, which is the only food on the list that does two jobs: our favorite snail food is Easy Shrimp and Snail Shells because they not only provide calcium, plankton, and spirulina in their diet, but they also slowly dissolve to add more calcium to the water. It also names Hikari Crab Cuisine and Repashy gel food for the mystery snail.
Calcium is not a supplement, it is most of the animal
Aquarium Breeder gives the figure that reframes the whole question: about 95 to 98% of a snail's shell dry weight is calcium carbonate. For comparison, the same page puts a shrimp's shell at about 30 to 50% calcium carbonate. A snail is a soft body carrying a mineral it has to source.
It also states where the mineral comes from, and food is the second route rather than the first: like fish, shrimp can absorb calcium from the water and the diet, and if there is enough calcium in the water they will obtain the majority of their calcium through their gills. Calcium in the diet, it says, will cover the deficiency of minerals in the water. And it adds a behavioral note: they can sense calcium concentration in their environment and prefer to live in a high-calcium environment.
So hard water does most of the work, and food is the fix for soft water. That is the same conclusion Aquarium Co-Op reaches from the symptom, telling keepers with soft tap water and eroded shells to increase the minerals in their water and food.
The vegetables, with numbers
Aquarium Breeder is the only source on this guide that publishes calcium content, in milligrams per 100 g:
- Kale, 137. The highest on its list, and the vegetable Aquarium Co-Op names for mystery snail shell growth.
- Spinach, 99. Also named by Aquarium Co-Op. Asked about oxalates in its own comments, that source answers that it has never had a problem with spinach, which we print as one keeper's experience rather than as a finding.
- Chinese cabbage, 74.
- Broccoli, 40. Also on its blanching list.
The non-vegetable sources, and how to prepare them
Cuttlebone, in that source's words, slowly dissolves in the water and releases a ton of calcium. Eggshells need work first: boil eggshells in hot water for 5 to 10 minutes to kill any harmful bacteria, dry them, then roast them in an oven or microwave for 5 to 10 minutes.
Antacid tablets are the one it hedges on. Tums dissolve very fast, therefore they can affect the water parameters, and its advice is to add a quarter of the tablet to see the shrimp or snail reaction. Its warning about the whole category is short: if you notice that levels are consistently too high or rising, remove additional mineral sources.
How to blanch a vegetable for a snail
Three of our five sources say blanched and only one explains what that means. This station is that one source, quoted, because a method with times in it is worth more than another list of foods.
Why bother. Aquarium Breeder: blanching means that we will soften them up, and as a result it will be easier for the fish, shrimp or snail to eat them. It will also make them sink to the bottom so they do not float on the surface of the tank. Both halves matter for an animal that cannot swim up to its food.
- Peel it. The source is firm about this and calls the alternative a mistake: it is easier to take the peel off and do not worry about what is actually on the peel.
- Boil for 1 to 3 minutes. The blanching process usually takes 1 or 3 minutes, and when you notice that the pieces start changing color it is a sign that they have softened and are ready. In a microwave, 15 or 30 seconds will be enough to break down the cucumber that it can be easy to eat.
- Cold water afterwards. When the pieces are finished blanching we are going to put them into cold water, and you need to keep the vegetables in the cold water until they are completely cool.
- No salt. I do not add salt for a freshwater tank: salt breaks down the vegetables over time and it makes them mushy, and by adding salt you are risking to change your water parameters.
- Sink it if it floats. If your vegetables are still floating you can use a fork or a little clip to sink them.
- Take it out again. It is advisable to remove any uneaten portions after 24 hours.
- Freeze the rest. Portion it, let the water drain before it goes in the container, because if you let the water get into the container and you freeze it, the pieces will stick together. Then you do not have to do anything other than pulling it out and dropping it in the aquarium.
The one warning on that page is about the vegetable rather than the method, and it is the reason to think about where the zucchini came from. The source reports keepers who had massive die-offs right after feeding, and says this is probably because the zucchinis were treated with pesticides. Its conclusion is two words: safety comes first. Nothing else we read raises pesticides at all, and we print it as one source's account rather than as an established cause.
How often? Nobody publishes a schedule
This is the question the keyword is really asking and it is the one our sources will not answer. Not one of the five publishes a feeding frequency for an aquarium snail. No times per week, no portion, no gap between meals.
What two of them publish instead is a rule for taking the food back out, which is a different and arguably better instruction:
- Aquarium Breeder: it is advisable to remove any uneaten portions after 24 hours.
- Aquarium Care Basics: generally, if a snail is not interested in a vegetable or food supplement after a day or two, remove it from the tank.
Read together, those two say offer, watch, remove rather than feed on Mondays. That is consistent with the animal being a scavenger whose main supply is the tank itself, and it puts the frequency where our sources implicitly leave it: you feed a snail when the tank is not feeding it, and you find that out by whether the food disappears.
We are not going to convert that into a schedule. For comparison, our animal records that do carry a feeding frequency got it from a source that published one: the african dwarf frog record has four sources giving four different frequencies, and the discus record has one giving 2 to 3 minutes of eating once or twice a day. On snails, the same publishers say nothing.
Will it eat my plants? One exception, and it is named
Three sources answer and they answer the same way, with one specific exception between them.
Aquarium Co-Op on the nerite: they are completely safe for aquarium plants and only eat unhealthy or dead vegetation. On the mystery snail: unlike their larger apple snail relatives, they won't eat your plants, and if you see your mystery snail eating a healthy plant, most likely they are actually nibbling on melted or sickly leaves for you. Our nerite snail record carries Shrimp Science saying the same thing in the same words a keeper would use, that it will only eat the decaying parts of a plant.
The exception is duckweed. Aquarium Co-Op states it directly: the one exception to the mystery snails don't eat healthy plants rule is duckweed. Duckweed is in the queue on our plants silo, named on our guppy record and with no page of its own yet, so this site cannot yet tell you how to keep the one plant a snail is documented to eat.
Aquarium Care Basics is the source that records the opposite belief without endorsing it: some hobbyists say that mystery snails will devour live aquarium plants. It does not take that position and neither do we, and it is printed here because a claim that circulates is worth naming even when the sources reject it.
Our three plant records all sit on the other side of this. The java moss record carries a source rejecting the one claim anybody makes against shrimp on that plant, the java fern record has five sources saying almost nothing will eat it, and the hornwort record prints two sources that disagree about goldfish. Snails are the one animal group our plant records are consistently relaxed about.
What this guide will not answer
How often to feed
No source publishes a frequency and we are not inventing one. Station 06 prints the two removal rules that exist instead.
How much to feed
Not one of the five gives a portion, a weight or a piece size. The nearest anybody comes is the instruction to remove what is left after a day.
Land snails
Half the traffic for this question is about a pet or garden snail in a tub with a piece of carrot. This site holds no sources on terrestrial snails and this guide is not about them.
Whether spinach is a problem
Oxalates in spinach come up in the comments under one of our sources, and that source answers with its own experience rather than with evidence. We print the exchange and not a conclusion.
Snail eggs
What a snail lays is not a feeding question and it is the question that follows one, because a well fed snail is a breeding snail. Our breeding page carries snail eggs as the largest single question on it by search demand, and our nerite snail record carries the reason that species is the exception: its eggs do not hatch in fresh water. Nothing in this guide changes either, and no source here connects a diet to a clutch size.
Which snail you have
This guide covers what our sources say about nerite and mystery snails, which are the two they write about. Four more snails sit in the queue on our snails silo, including the ramshorn and the bladder snail that arrive on plants uninvited, and nothing here is verified for those. The A to Z index is the list of what exists.
Whether a supplement changed the water
One source warns that antacid tablets dissolve fast enough to affect water parameters and says to start with a quarter tablet. Nobody publishes a figure for how much any calcium source raises hardness, so the instruction is to test rather than to calculate.
Snail feeding questions, answered from the sources
What do aquarium snails eat?
Whatever the tank produces, first. Aquarium Co-Op describes both nerite and mystery snails as scavengers eating algae, biofilm, leftover fish food, dead fish and decaying leaves. Aquarium Care Basics adds soft filmy algae on plant leaves and glass, and shed plant matter on the bottom. When that is not enough, the named supplements are algae wafers, blanched zucchini, canned green beans, blanched spinach or kale, lettuce, bottom feeder tablets and crab or shrimp foods.
Do I need to feed my snail at all?
It depends on the tank, and the risk of assuming not is stated plainly. Aquarium Co-Op: nerite snails can starve to death if there is not enough algae in the tank or other fish are outcompeting them for food. A mature planted tank with light stocking usually feeds them. A new or bare tank, or one with fast greedy fish, does not.
How often should I feed a snail?
None of our five sources publishes a frequency. Two publish a removal rule instead: Aquarium Breeder says to remove any uneaten portions after 24 hours, and Aquarium Care Basics says that if a snail is not interested after a day or two, take it out. The practical reading is to offer food, watch whether it disappears, and let that set the rhythm.
What vegetables can snails eat?
Zucchini, cucumber, carrot, broccoli, lima beans, cabbage and lettuce are named by our sources, along with spinach and kale specifically for calcium. All of them blanched. No source we hold names a fruit, and Aquarium Breeder says why it would not: fruits contain lots of sugar.
How do I blanch vegetables for snails?
Peel it, boil it for 1 to 3 minutes until the color changes, then cool it completely in cold water. A microwave version takes 15 to 30 seconds. No salt, because it makes the vegetable mushy and risks the water parameters. Sink it with a fork or a clip if it floats, and remove what is uneaten after 24 hours. Blanching does two jobs: it softens the vegetable and it makes it sink.
Why does a snail need calcium?
Because the shell is almost entirely made of it. Aquarium Breeder: about 95 to 98% of a snail's shell dry weight is calcium carbonate, against 30 to 50% for a shrimp shell. It also says most of the calcium comes through the gills from the water when the water has enough, and that dietary calcium covers the deficiency when it does not.
How do I add calcium for a snail?
Four ways from one source. Calcium-rich vegetables, blanched, with kale at 137 mg per 100 g, spinach 99, Chinese cabbage 74 and broccoli 40. Cuttlebone, which slowly dissolves and releases a ton of calcium. Eggshells, boiled 5 to 10 minutes and then roasted 5 to 10 minutes. And antacid tablets, which dissolve fast enough to move your water parameters, so start with a quarter of one. Aquarium Co-Op names a commercial food that dissolves calcium into the water as it is eaten.
My snail's shell is cracked or pitted. What is wrong?
Two sources point at the same thing. Aquarium Co-Op: if you have soft tap water and notice your snails are getting cracked or eroded shells, increase the minerals in their water and food. Aquarium Care Basics: cracked, thin or excessively pitted shells can be signs of calcium deficiency, and periodic calcium supplements may be necessary. Both put the water before the food.
Will snails eat my aquarium plants?
Our sources say no, with one named exception. Aquarium Co-Op: nerites are completely safe for aquarium plants and only eat unhealthy or dead vegetation, and mystery snails won't eat your plants, though duckweed is the one exception to that rule. Our nerite snail record carries Shrimp Science saying it will only eat the decaying parts of a plant. Aquarium Care Basics records the opposite hobbyist claim without endorsing it.
Can I feed a snail fish food?
Yes, and two sources treat it as normal rather than as a compromise. Aquarium Co-Op says a mystery snail's aquarium diet usually consists of fish food, algae, biofilm, dead fish and dead plants. Aquarium Care Basics names bottom feeder tablets, pellets, fish flakes and algae wafers. Aquarium Co-Op also names crab and shrimp foods, which are the same idea with more protein.
Do nerite and mystery snails eat the same things?
Nearly, and one source draws the distinction that matters. Aquarium Co-Op: some hobbyists find mystery snails to be hardier but not as good at algae eating as nerite snails. It also names the nerite as one of the few animals that will eat green spot algae. So the nerite is the more specialized grazer and the mystery snail is the more general scavenger, and the mystery snail is the one our sources push calcium-rich vegetables at.
Is this guide about pet land snails?
No. Roughly half the search traffic for this question is about a terrestrial pet or garden snail, fed on a dish out of water with carrot, cuttlebone and no citrus. This site compiles freshwater aquarium sources only and holds nothing verified about land snails, so it says so rather than repeating what it has not checked.