Introducing some bottom feeder fish to your tank is a fun way to augment the aquarium while helping to keep it clean. These fish perform useful housekeeping duties by using tank waste as their primary form of sustenance.
You have quite a few choices when it comes to bottom feeding fish. The varieties listed here are readily available for purchase at most fish stores. Each one has its own unique personality, set of behaviors, and care requirements. Take time before deciding which one will make the perfect addition to your home habitat.
11 Popular Bottom Feeder Fish: Our Top Picks
The following recommendations are general guidelines, so always check with the breeder or pet store you purchase your bottom feeder from for specific care instructions.
Kuhli Loach
The long eel-like Kuhli loach makes a great aquarium companion, and not just for the housekeeping services it provides. Kuhlis are adept hiders, and love slinking around the tank finding places to burrow underneath or behind. Their coloring and bold stripes are distinctive and beautiful.
Personality and Compatibility
Kuhlis are notoriously peaceful. They prefer schooling with a handful of other Kuhli loaches. A Kuhli kept by itself will likely spend most of its time cowering and hiding away. They are best kept with non-aggressive species of fish. Generally speaking, you probably shouldn’t place Kuhlis in the same tank as Cichlids, or with any aquatic animal you have seen displaying aggressive behavior.
Care and Habitat Tips
Kuhli loaches like to burrow under their tank substrate, so it’s best to use sand or very fine gravel so they are not injured by jagged rocks. Loaches can easily swim into filter inlet tubes, so these must be covered with some type of screen. Always impressive, the Kuhli is also quite capable of jumping right out of the tank! You’ll want to have a secure lid for any aquarium housing these athletic fish.
Kuhlis do most of their business at night, so you may want to add a nighttime viewing light. They are omnivorous, and will eat plant-based food as well as live food. You can feed them glass worms, blood worms, daphnia, and tubifex in addition to their regular diet of tank debris.
Size and Lifespan
This bottom-feeding fish grows to about 4 inches long in adulthood. A healthy Kuhli loach can easily live for 10 years.
Zebra Loach
Personality and Compatibility
Zebra loaches are friendly and usually quite peaceful, but they aren’t shrinking violets either. They are enthusiastic and love to play (which can be off-putting to more docile fish). They get along great with other loaches, and will even school with them. On that note, be sure to place Zebra loaches with at least a few other loaches. While they get along pretty well with most fish species, these small loaches are not ideal tankmates for the aforementioned Cory catfish since the two are known to compete for territory.
Avoid putting Zebra loaches in the same tank with fish that have long fins or tails (such as bettas and angelfish). This is because your otherwise friendly little Zebra loach might just take a nip at those trailing appendages.
Care and Habitat Tips
Unlike most other loaches, Zebras aren’t nocturnal. However, they still require plenty of places to play hide and seek. A proper habitat for Zebra loaches should have plenty of plants, rocks, logs, or other features.
Zebras require a soft substrate since they enjoy burrowing beneath it. Sand is a good choice. You can use rock or gravel, as long as it’s not rough or jagged. They are a bit less tolerant of water condition changes than some other bottom-feeders, so take extra care to change the water regularly and to monitor everything closely. They also aren’t big fans of really bright lights, so keep the lighting fairly dim.
The omnivorous Zebra loach will eat lots of other things in addition to scouring your tank for tasty detritus. They particularly love bloodworms, daphnia, tubifex, glass worms, and brine shrimp. While live is best, you can purchase frozen or freeze-dried versions at pet stores or online.
Another note about the Zebra loach’s diet: they find snails to be quite delicious. This can be great if you have unwanted snails in your tank. Otherwise, not so much.
Size and Lifespan
Zebra loaches are relatively small, and usually grow to be no more than 4 inches long. A well cared-for Zebra loach can live for up to 10 years.
Yoyo Loach
The YoYo loach is sometimes called the Reticulated loach because of its distinctive patterning. While stories vary, the general consensus is that the YoYo gets its name because these markings often resemble “Y”s and “O”s.
Personality and Compatibility
Yoyo loaches are a favorite among hobbyists because they seem to have more personality than many other types of bottom-feeders. Some YoYo loach owners will tell you that their YoYos will respond to their presence, and even “play” with them from behind the aquarium glass. They are peaceful fish, but can be somewhat aggressive when placed with the wrong tankmates.
It’s preferable to keep your YoYo loach with a group of similar fish, as they like to run in little packs. It’s also best to avoid placing too-aggressive or too-docile fish in the same tank as your YoYo. Fish that are too timid might get bullied by the gang of YoYo loaches.
Care and Habitat Tips
YoYos are fairly particular about water conditions, so keep close watch on temperature, pH, and cleanliness in your tank. They are nocturnal, and they enjoy digging around in the substrate of their tank. In fact, they may even burrow underneath and hide there. This being the case, keep YoYo substrate soft and fine. Sand is a great choice. While known for their fun personality, note that a newly added YoYo might be a bit shy as it gets accustomed to its surroundings.
YoYo loaches prefer animal-based foods such as bloodworms, brine shrimp, and various insects – and, like other loaches, will happily gobble up any snails in the tank. However, they will also eat algae and other herbivorous foods.
Keep a good lid on your tank, as YoYo loaches can jump out.
Size and Lifespan
YoYo loaches grow to be about 3 to 5 inches long in captivity. However, wild YoYos can get longer. They generally live around 5 to 10 years, but there are some known cases of these fish living for 15 years or more.
Size and Lifespan
Cory catfish are compact, growing to no more than 3 inches in length. They can live for quite a long time when properly cared for. While Cories live for only about 5 -7 years in the wild, captive specimen can live for 15 years or more.
Bristlenose Plecostomus
Personality and Compatibility
Bristlenose plecos are pretty laid-back creatures. They get along well with most other types of fish. Just don’t place them with particularly aggressive fish that might attack or harass the peaceful pleco. They are interesting to observe, as they happily move around the tank, skimming algae from its surfaces.
Care and Habitat Tips
The Bristlenose pleco generally prefers a mostly plant-based diet. Bristlenose plecos enjoy aerated water with some movement. These nocturnal fish do most of their playing and eating during the night. They need plants, rocks, and other things to hide behind during the day. Avoid anything that could harm their sensitive barbels, though.
Plecos will munch on algae and other goodies left behind by tankmates, but often need some dietary supplementation for optimal nutrition. You can buy pleco food from most pet stores.
Size and Lifespan
The Bristlenose plecostomus grows up to about 6 inches long, which is a great size for many home tanks. It’s big enough to clean up a substantial amount of tank waste, but not so big that it crowds the tank (for reference, the Common plecostomus grows up to about a foot long).
Cory Catfish
The Cory catfish comes in several colors and sizes. The hard plating that covers their bodies makes them a particularly hardy fish. Their most distinguishing features are the whisker-like appendages – called barbels – that extend from their faces.
Personality and Compatibility
Cory Catfish, or Cory Cats, have a mellow temperament and are pretty easy to take care of. They are the opposite of aggressive. They get along with all kinds of different aquatic creatures. This gentle nature can get the Cory Cat in trouble if it’s housed with a fish that likes to fight, since the Cory won’t defend itself. Keep this in mind when deciding whether a Cory would be a good fit for your tank.
These friendly fish prefer to be part of a group, so it’s best to bring home a handful of Cories. Swimming in schools isn’t just essential for optimal health, these fish display a brighter personality when they have a few buddies to play with. Watching a small school of Cory catfish engage in their signature synchronized swimming routine is actually quite enchanting.
Care and Habitat Tips
In the wild, Cory catfish live in streams and rivers. Here, they enjoy hiding among plants and rocks. In captivity, their habitat should be outfitted accordingly. When it comes to substrate, these fish prefer sand to gravel. This is because rough-edged substrate can cut them. They enjoy water with some movement, which mimics the flowing water of their native habitat.
Cory catfish like most aquatic plants. Some easy-to-find varieties your little Cory will love include:
- Java Moss
- Java Fern
- Hornwort
- Pennywort
Types of Cory Catfish
Albino: The pinkish-white albino Cory is striking to behold. They are also known to have a very lively temperament.
Peppered: Known for its distinctive speckled markings, this Cory catfish variety is popular and usually easy to find.
Panda: Panda Cory catfish are also really easy to find. Their name comes from their light-colored body and dark markings around the head and tail.
Pygmy: The pygmy Cory only grows to around 1 inch long. Another thing that sets this little fish apart from its relatives is the fact that it likes to swim around in the middle part of the tank instead of hanging out on the bottom all the time.
Sterbai: Easily one of the most attractive Cories, the Sterbai (also called Sterba’s Cory) displays a gorgeous spotted pattern.
Julii: This Cory variety is beloved for its beautiful striping, which resembles an intricate maze. Since true Juliis are quite rare, the ones sold in pet stores are often False Juliis.
Otocinclus Catfish
You may see the Otocinclus catfish referred to as the Otto, Otto Cat, Dwarf Sucking Catfish, and Midget Sucker Fish. They appear different than one might expect of a catfish, as they don’t display the signature “whiskers.”
Personality and Compatibility
Peaceful and non-confrontational, Otocinclus catfish get along with other non-aggressive fish. They do well with Cory catfish, and with most varieties of freshwater shrimp and snails. Bad tankmates for the Otto include cichlids, oscars, goldfish, and convicts. These species may fight with – and even kill – an Otocinclus catfish.
You should always place this fish with a few others of its kind, as Ottos thrive in small schools.
Care and Habitat Tips
Ottos are herbivores, and love nibbling at algae that accumulates on surfaces around the aquarium. Some will eat bits of zucchini when offered, too. Algae wafers work for dietary supplementation. Experts recommend placing them in an established tank that has plenty of aquatic plants and hiding spaces for this small, shy fish.
These little fish require consistent tank conditions, and drastic changes in temperature or other variables can be fatal.
Size and Lifespan
This little catfish only grows to around 1 or 2 inches long in adulthood. In the right conditions, they can live for up to 5 years.
Twig Catfish
The Twig catfish is named for its long, thin appearance – which is not unlike that of an actual twig.
Personality and Compatibility
Aside from their unique appearance, the behavior of this fish also sets it apart from the crowd. Twig catfish aren’t into swimming around leisurely. Instead, they are most often found attached to the surface of something in the tank. When they’re ready to move on to something else, they’ll quickly flit over to it. This is mostly a survival mechanism; the Twig tries its best to always look like its namesake. It’s so committed to this, that the Twig catfish will often remain motionless even upon capture.
Twigs are totally non-aggressive, and might get picked on by other fish. Take care when considering this fish as an addition to your community tank. In most cases, these fish do best when placed with the same or very similar species.
Habitat and Care
As you already know, these little fish look just like a tiny twig. This means they can easily blend in with the landscape features in many aquarium habitats. You may find yourself playing “spot the Twig” in your tank on a regular basis. Twig catfish demand exceptionally clean water. It’s easy for toxins and debris to build up in a smaller tank, so take this into account when deciding whether you’ll be able to keep up with the water condition needs of this bottom-feeder.
Size and Lifespan
While often quite tiny, these catfish have the potential to grow up to 6 inches long. They can live up to a whole decade. That said, it’s not very common for one to live that long since they can be so sensitive to changes in their habitat.
Siamese Algae Eater
Closely related to carp, these tank-tidying fish are easy to find at most pet stores and online shops. They are delicate and attractive, making a fantastic addition to many freshwater aquariums.
Personality and Compatibility
Siamese algae eaters are very peaceful fish, and rarely show aggression toward their tankmates. They’re also full of energy. There’s a reason the Siamese algae eater is sometimes called the Flying Fox. Their sporadic movements can upset fish that are more docile. Siamese algae eaters do best when given a group of friends to roam the tank with.
These fish are compatible with many other types of fish including Cory catfish, guppies, tetras, gourabis, and barbs. They also do well with most freshwater shrimp and snails. While it’s not necessary to keep them in schools, Siamese algae eaters will display the most entertaining behaviors if they a few pals to hang around with.
Habitat and Care
Siamese algae eaters are quite versatile; they are able to thrive under a variety of tank conditions. They usually don’t need much time to adapt to a new environment, and they will often start searching around for a snack the moment you add them to your tank. They prefer a heavily-planted aquarium, which gives them lots of opportunities to harvest algae build up – as well as providing hiding spots.
As you may have guessed, these fish primarily feed off of algae and other vegetable matter. However, they aren’t super picky eaters, and will eat pretty much anything they find around the tank. If you suspect your tank isn’t providing enough algae buildup to keep your Siamese algae eater satisfied, you can supplement with flakes, pellets, and even live food such as brine shrimp or bloodworms.
Size and Lifespan
Siamese algae eaters are fairly small. They typically only grow to be about 5 or 6 inches long, at the most. They are distinguished by their long lifespan; some have been known to live for 10 years.
Crayfish
Crayfish are fun little creatures to observe, looking as they do like tiny lobsters. Several varieties of this freshwater crustacean are available to purchase as aquarium pets. Depending on where you live, you might hear crayfish referred to as crawdads or crawfish.
Personality and Compatibility
There are many species of crayfish, but only a couple that are generally used as aquarium pets.
Crayfish aren’t always the best choice for community tanks, although many hobbyists have successfully housed them with other aquatic pets. Crayfish can be somewhat aggressive, although captive specimens may develop more docile behaviors than their wild counterparts.
The following fish are good options for keeping with small crayfish: platies, swordtails, neon tetras, and some small catfish. Larger crayfish can live with the aforementioned fish, as well as some larger species such as medium-sized catfish, some cichlids, barbs, and goldfish.
A crayfish can be a very entertaining pet, displaying all kinds of unique behaviors and abilities.
Habitat and Care
The omnivorous crayfish eats lots of things. In the wild, it will eat basically anything it can get its claws on. In a tank, it will eat plant and waste matter that accumulates. You’ll also need to provide it with plenty of extra snacks (unless you want to risk a tankmate becoming said snack).
These crustaceans don’t make much fuss about water conditions, but they could crawl out of the tank – so get a secure top. As crustaceans, they will shed their exoskeleton and replace it with a new one from time to time. Once they have lost a shell, it takes a while – anywhere from days to weeks – for the new one to form. During this time, the crayfish will be particularly vulnerable to injury from objects and animals in the tank. Because of this, it will probably spend a lot of time hiding out.
Size and Lifespan
Crayfish range in size, from tiny species that don’t grow much longer than an inch to larger ones that can get over a foot long.
Snails
Lots of people add freshwater aquarium snails to their tank to help keep it clean. Snails can also bring a whimsical touch to any aquatic environment. There are several varieties that work well in a community aquarium. Nerite snails, Inca snails, and Ivory snails are all popular varieties for hobbyists. While there are plenty of other types of snails that can be placed in your freshwater aquarium, take care when selecting them. Some species can breed so rapidly that their population can quickly grow out of control (the Rabbit snail is so named for this exact reason). Others – namely the Assassin snail – will kill any other snails in the tank.
Personality and Compatibility
With the exception of the Assassin snail, freshwater snails tend to be pretty peaceful little creatures. They make good roomies for most kinds of freshwater fish. More aggressive fish and animals may try to attack snails.
Habitat and Care
Snails are quite low maintenance by nature, and they will happily spend their lives traveling slowly around the tank eating up waste and debris. They do need to have fairly stable water conditions though, so avoid abrupt changes to their environment. Never use soft water for a tank with snails in it; they need the calcium in hard water to keep their shells healthy and strong.
Snails will explore every possible place they can. Make sure they can’t access areas where they could get hurt, such as the outside of the tank or inside of the filter mechanism.
Size and Lifespan
In the wild, snails don’t tend to live more than a few years. This is because they are, frankly, easy prey for many of the creatures they share the water with. When kept as pets, snails can live for a decade or more. Freshwater snails vary in size and shape, depending on the species. Some never make it to the one-inch mark, while others can grow two inches or longer.
Freshwater Shrimp
A freshwater shrimp makes a particularly cute addition to your tank. They keep busy nibbling away at algae growth around your aquarium, and they’re pretty fun to watch as they do this. There are quite a few varieties that have become available, with an array of colors and patterns.
Personality and Compatibility
Small aquarium shrimp typically keep to themselves, and don’t pose much of a threat to those they share space with. They can be kept with small, docile fish like Ember tetras, gouramis, rainbow fish, otocinclus, and pygmy Cory catfish. They can also cohabitate with most freshwater snails.
Habitat and Care
Each species of freshwater shrimp requires specific water conditions, so check with the breeder or pet shop when you buy yours. All of them are sensitive to high levels of nitrates and ammonia, so it’s important to properly cycle your tank before introducing them.
While they do feed on tank algae, most shrimp will happily gobble up whatever else you put in the water. Just be careful not to overfeed. Don’t supplement so much that your shrimp stops cleaning your tank.
Size and Lifespan
Freshwater shrimp vary in size by species. Some are less than an inch long. Others may grow to be around 5 inches or so. Smaller varieties typically live for a couple of years, while some of the larger species have been documented as living 10 years or more in captivity.
A Few Notes on Keeping Bottom-Feeders in Your Aquarium
- Always ask for species-specific care instructions for any bottom-feeder you plan to bring home.
- Be sure you’re providing a big enough tank for the fish you select.
- Take care to choose tankmates that require similar habitat conditions.
- Take the time to cycle your tank before introducing these and other aquatic animals.
- Never use any kind of tank landscape objects that have sharp edges or too-small openings which could result in injury to your pets.
- If you supplement your bottom-feeder’s diet, watch to ensure they are getting their fair share. Other fish in the aquarium may gobble up the food you add before it gets to the bottom feeders. This is why sinking food pellets (rather than the ones that float) are often ideal.
- Don’t overstock. Adding too many fish to a tank isn’t just unhealthy (and not very nice) to your pets, it can negate the effects of adding algae eaters to your tank in the first place.
