In the aquarium hobby, there are typically three zones in your tank that you want to consider when stocking to ensure you have an even spread of fish: there are surface feeders, mid-water fish, and bottom feeder fish. Bottom feeder fish live and feed on the lower section of the aquarium where they can bring a great addition of life and color!
Which bottom feeder fish species are small and easy to keep in a freshwater aquarium? We’re going to take a look at five of the most common bottom feeder fish available and discuss their appearance, behavior, dietary needs, and preferred tank conditions.
This article on bottom-dwelling aquarium fish is a guest post by Robert from Fishkeepingworld.com, an aquarium website dedicated to educating fish enthusiasts all over the world. Thank you, Robert!
What is a bottom feeder fish?
Many bottom-feeding fish are adept at burying themselves in the substrate; they also usually have a flat underside which is useful for resting on the bottom of the tank. One common thing most of these fish share is their ability to help keep the bottom of a tank clean due to their downward-pointing mouths. That’s why bottom feeder fish are often known as part of the ‘cleanup crew’ and essential for helping keep a tank clean. However, there are some species whose mouths point upwards, too.
Some bottom feeders are detritivores, meaning they search for food that is made up of both decomposing plant and animal matter. Others are strict carnivores that feed on fish and other animals. Some bottom-feeders grow too large for most regular home aquarium setups and should be avoided while others make the perfect addition for a small tank.
A great example of a species that gets too large for the average tank is the common pleco, even though it is regularly sold in fish stores. For this reason, we’ll focus only on smaller bottom dwellers suitable for the average home aquarium setup.
Bristlenose pleco (Ancistrus sp.)
We mentioned briefly above that although fish stores usually sell Hypostomus plecostomus, also known as the common pleco–which look very cute as babies at only 2-4 inches (5-10 cm) in the store–they can quickly grow to 20 inches (50 cm) long. This species is just way too big for most regular freshwater aquarium setups and does much better in outdoor ponds and lakes where there is plenty of algae for them to eat and space to grow.
A good alternative to these fish is the much smaller members of the Ancistrus genus, also known collectively as the bristle nose pleco. These algae eaters are in the same family (Loricariidae) as the common pleco, but only grow up to 4.5 inches (12 cm) long; this makes them a much more suitable species for a typical freshwater aquarium where you don’t have to worry about them quickly outgrowing the tank.
Bristlenose plecos come in a variety of colors with the most popular being brown with patches of lighter areas. Their mouths feature small appendages that look like short cat whiskers; these barbels are actually useful for sensing and finding food as it sinks to the bottom of the tank.
This is a peaceful fish species that is pretty easy to care for and fun to watch as they munch their way across the side of the aquarium glass. They require an omnivorous diet, so they are not picky eaters and will pick up all the leftover food lying around the aquarium. You can supplement with sinking pellets and algae wafers if you really want to make your fish happy.
As for tank conditions, these algae eaters will require a minimum tank size of 30 gallons (113.5 L). Provide these fish with plenty of hiding spaces throughout the tank by using natural plants and rocks.
Temperature: 74-79 °F/23.3-26 °C
Peppered Cory catfish (Corydoras paleatus)
The peppered cory catfish (Corydoras paleatus, pictured at the top) grows to around 2.3 inches (6 cm). This species of bottom feeders has black and green spots all over its body and a white underside. Again, this is a peaceful and easy fish to care for and is completely suitable for new aquarium keepers. These fish do their best and are especially fun to watch when kept in groups of 6 or more per tank.
Peppered cory catfish require an omnivorous diet, and therefore will need both plant- and animal-based food. You can feed them freeze-dried bloodworms, sinking fish, or shrimp pellets, as well as live food. They require a minimum tank of 10 gallons (38 L), which should be well-planted with plenty of hiding spaces, like coconut caves, so they can get away from the light. For the substrate, choose aquarium sand or very fine gravel so that your bottom feeders’ barbels don’t get damaged.
Temperature: 72-79 °F/22.2-26 °C
There are so many different species of loach suitable for home aquariums and they come in a wide variety of shapes and sizes. Some loaches, like the large clown loach, require moderate care and are more suited for experienced aquarium keepers. For that reason, we’ve chosen three species that are much easier to care for and more suitable for beginners who may just be starting out with a smaller tank.
Zebra Loach (Botia striata)
One of the gentler species of loach is Botia striata, also known as the zebra loach. These bottom-feeders grow to a similar size as most other community fish (around 3.5 inches/9 cm) and make an ideal addition to a community tank. As you would expect, given their name, they have a black and white striped color, with translucent fins and tail.
You should feed your zebra loach sinking catfish pellets as well as a variety of frozen food, such as brine shrimp and daphnia. They should be kept in a minimum tank size of 20 gallons (78 L), with a soft substrate so as not to irritate their barbels. Their tank should also include plenty of hiding spaces using driftwood, rocks, and caves.
Temperature: 73-79 °F/22.7-26 °C
Kuhli loach (Pangio kuhlii)
The kuhli loach is one of my favorite fish, and definitely at the top of my bottom feeder list for personality. They only grow to about 5 inches (13 cm) but can live up to 14 years if tank conditions are ideal. While kuhli loaches are very social fish and will interact with others of the same species and other bottom feeders, they don’t actually school together. Because of this, it is recommended to keep at least 5 together in a big enough aquarium of at least 31.5 inches (80 cm).
These fish have an eel-like appearance and are yellow with brown/black vertical stripes; they also have barbels around their mouth to help sense food nearby. Kuhli loaches are mostly carnivores, so they can be fed fish flakes or pellets but should also regularly be offered a variety of frozen and live foods, like brine shrimp and bloodworms. Keep in mind that these fish are not compatible with snails or shrimp before adding either to your tank.
You can learn more about keeping kuhli loaches in your own tank with this full care sheet.
Temperature: 74-79 °F/23-26 °C
Yoyo Loach (Botia almorhae)
The yoyo loach reaches a maximum size of 5-6 inches (13-15 cm) and is typically docile within a community tank community. However, they are highly active and almost constantly searching the substrate and the bottom of the tank for food, so other small and less active fish may tend to shy away from them. They need to be kept stimulated, so it is recommended to keep them in groups of at least 5. This will mean that you will need a tank of at least 40 gallons (151 L).
The yoyo loach earns its name from the black/brown striping on their creamish-tan body; the black stripes actually look like they form Y’s with the alternating open spaces looking like O’s, to form YOYO across their body. These fish also have small barbels and use them to locate food. They are mostly carnivores, but will also eat any fish flakes or pellets provided. Because of this, use caution when introducing any small invertebrates.
It is important to keep in mind that these fish will much prefer small spaces to hide in rather than any open caves you might have placed for them in your tank. Any decor added, like rocks and driftwood, should not have sharp edges as your yoyo loach could hurt itself when squeezing itself into these spaces!
Temperature: 75-80 °F/24-27 °C
Species of Otocinclus usually do best in groups of at least 6 per tank. These bottom feeders are one of the smallest fish in the catfish family (Loricariidae). They have a black peppered body and grow to around 4 inches (10 cm). They have a peaceful temperament and can usually be kept with other small fish in a community tank, but are unfortunately not the easiest fish to care for due to their specific diet: Otocinclus are herbivores and so they require a diet of plant matter, vegetables, and algae wafers. They are one of the most well-known algae eaters and they will use their sucker mouth to clean rocks, glass, and all the surfaces in your freshwater aquarium.
Otocinclus require a minimum tank size of 10 gallons (38 L) that is densely planted with plenty of rocks and driftwood for additional hiding. These bottom feeders will also need a fine aquarium substrate with a good filtration system and high aeration.
Want to know more about keeping Otocinclus in your own aquarium? You can find a full care sheet for these fish here.
Temperature: 74-79 °F/23.3-26 °C
Twig catfish (Farlowella sp.)
The twig catfish (Farlowella sp.) is one of the larger bottom feeders to be featured in this article. They typically grow to around 6 inches (15 cm). Their name is derived from their incredible ability to camouflage in the wild: these fish look like twigs! These fish are very long and thin, have an elongated nose, and a beautiful black and brown coloration. These peaceful community fish are fairly easy to care for and make a great addition to any aquarium!
Twig catfish are omnivores, so their diet should consist of algae as well as bloodworms and frozen foods. They will get most of their nutrition from leftover fish food and algae on the bottom of the tank, but always be sure to keep an eye on them to make sure they’re eating enough.
These fish require a minimum tank size of 50 gallons (189 L). The aquarium should be planted and have plenty of rocks and driftwood. They also require high aeration.
Temperature: 73-79 °F/22.7-26 °C
Bumblebee goby (Brachygobius sp.)
In search of a bottom dweller for your brackish aquarium? The appropriately named striped bumblebee goby might be the fish you are looking for. This tiny goby is most suitable for a small aquarium and, with the right care, can be a real joy to keep and fun to watch.
The most important thing to keep in mind about bumblebee gobies is that in most cases, they’re best off in a single-species tank set-up with at least 6 of their own species. These bottom feeder fish can be relatively shy and might not always be able to compete for food with other aggressive and more active fish.
Make sure to keep your bumblebee gobies in a low-end brackish aquarium with a sandy substrate. Provide plenty of hiding places in the form of caves and tubes. Happy bumblebees will display fascinating behaviors: you’ll always see them squabbling over territory and chasing each other around the tank, though no fish actually tend to get hurt.
Want to learn more about keeping bumblebee gobies from the Brachygobius genus in your own aquarium? Have a look at the full bumblebee goby care sheet.
To keep in mind about bottom feeder fish
Bottom dwellers are usually great at cleaning up bits of algae and uneaten food that has been missed by the other fish and has sunken to the bottom of the tank. However, they usually can’t solely survive off these leftover pieces and you should make sure to provide them with additional food, such as sinking pellets, to ensure their diet is being fully satisfied.
Bottom feeder fish can add color and personality to your tank, making them fun to watch as they zoom around the bottom section of your tank. Always carry out plenty of research for each fish species before you add them to your aquarium; make sure they will get on well with the fish you already have and check that they won’t quickly outgrow the tank.
If you have any more questions about these bottom feeder fish or want to share your own experiences with one of the fish species on the list, don’t hesitate to leave a comment below!