From The Aquarium Wiki

The 38 Litres (10 US G.) tank, sometimes called a 10 long, is one of the most well known sizes for beginner tanks, and yet is remarkably restricting on what creatures can truly thrive in this amount of water. In terms of tank sizes, 38 Litres (10 US G.) is classed as small. If you have found yourself with this size tank and are wondering what to do with it without having to plan extensive tank upgrades, read on.

This is, by no means, a definitive list, but we have tried to include the most commonly found fish in fish stores, we have not included very rarely found fish. There are of course, plenty of other fish that could be options, feel free to suggest any in the "discussion" tab above.

Fish suitable for a 10 Gallon tank

The following fish can truly live in a 38 Litres (10 US G.) tank for their entire lives. The majority of suitable fish will not grow larger than 5.1cm (2") in length and prefer tropical temperatures. Please note that this list does not mean you can add them all into the tank together! Or indeed one of each. Read further on for stocking ideas.

Community Options

These fish will tolerate being in a peaceful community setting with other peaceful tank mates.

The Betta is an excellent candidate for a 38 Litres (10 US G.). A single male would happily patrol this size tank and can be kept with small nondescript bottom dwellers. Or you could have a sonority of 5-6 females, these would have to be added carefully, and all at one time and need plenty of hiding places. If stocking with a single male, it must be added carefully and décor should be soft and rounded, no jagged edges, and the filter must be gentle as long-tailed male Bettas are not strong swimmers. Bettas should never be kept with Gouramis.

The Honey Gourami is a colourful addition to a small community tank. They are generally peaceful, but two males can be aggressive to one another. For a 38 Litres (10 US G.) it's best to keep either a single male, a single female or a male/female pair. Due to their long ventral fins, they should not be kept with nippy fish.

Not as colourful as the Honey Gourami, the Sparkling Gourami is still an attractive little fish, never growing more than 2.5cm (1") in length. These little fish do best kept in trios of one male with two females. If two males are kept in the tank there may be aggression issues. These Gouramis will even "croak" or "sing" when breeding or deciding territories.

These are effectively the wild cousin of the Guppy and indeed male/female groupings will multiply with surprising speed, unlike Guppies, they do NOT eat their own fry. However, due to their small stature (1" for females, just under 1" for males), they are perfectly happy living in a 38 Litres (10 US G.) peaceful community, or species, tank. If you don't want to be inundated with babies, the colourful males can be kept without females. These can often be found in stores as hybrids with the Guppy, these hybrids may be a little larger than a true Endler. As with all livebearers, if you are considering a mixed sex group, keep one male per three females. If you are keeping a single-sex group, keep 4-6 individuals.

Another small livebearer, a little less colourful than the Endler above, but still capable of reproducing at an exceptional rate. Again, if you wish to note be inundated with fry, keep a single sex group. Females are a little larger than males but will not grow any larger than 2.5cm (1"). These are entirely peaceful little fish, but do not confuse them with Gambusia affinis which grow larger and can be nippy and aggressive. The Dwarf livebearer is a sociable little fish, if a single-sex group is to be kept, do not keep any less than 4 individuals.

The Ember Tetra is a tiny little fish that does best in a shoal of 4-5 or more. In a 38 Litres (10 US G.) go for 10 max if they are the only fish in the tank. Each fish will not grow larger than 2.5cm (1") and they are rich orange-red in colour and look stunning against a planted lush green backdrop. Do not keep with long-finned fish just in case they decide to nip.

A sociable peaceful shoaling little Rasbora that will not grow more than 2.5cm (1") in length. Keep this little fish in groups of 4-6. Not nippy and not aggressive this fish does well in the smaller surroundings of a 38 Litres (10 US G.) and looks stunning in a planted tank.

Requiring almost identical care to the Dwarf Rasbora above, this little fish gets a little larger at 3.8cm (1.5") max and has attractive blue-green colouration with vertical stripes. It is an entirely peaceful shoaling fish, 6 would work in a 38 Litres (10 US G.).

This is one of the few true dwarf Corydoras catfish available, never growing larger than 1" in length. As with all Corys, this little fish is very sociable and entirely peaceful and should be kept in a group of 4-5. The C.habrosus will spend the majority of its time on the substrate, and so the substrate should be soft, preferably sand, to avoid damage to their tiny delicate barbels.

Similar to C.habrosus but more of a mid-swimmer. Again, entirely sociable and peaceful and should be kept in a group of 4-5. This Cory is not often seen for sale.

Like the C.hastatus, this little cory is also more of a mid-swimmer than the bottom-dwelling C.habrosus. Like the other Corys, the Pygmy Cory does best in group of 3-5. This fish is more often seen tha the C.hastatus.

The Oto is an entirely peaceful little suckermouth catfish usually growing to about 3.8cm (1.5") in length. It does best in groups of 3 (or more, but more than 3 really needs to be in a larger tank than 38 Litres (10 US G.)). It must be noted that this little fish can be a high waste producer and must only be added to mature tanks with plenty of algae, they are especially partial to brown algae but should be supplemented with other foods, they won't eat all types of algae. They need a lot of hiding places as they can get spooked by activity outside the tank.

These are peaceful top-dwelling shoaling fish that only get to about 2.5cm (1") in length. They should be kept in groups of 6 and there must be a tight fitting lid with no gaps as these fish will jump, especially if they see food or are startled. Do not keep with anything that may bully them.

This Minnow is popular with beginners and often marketed as "coldwater", it is in fact sub-tropical and will happily tolerate low-end tropical temperatures, and will benefit from the stability of a heated tank. They love a highly oxygenated tank and a good current. They are active little shoaling fish and no less than 4-5 should be kept. Due to their active nature they will generally appreciate a larger space than a 38 Litres (10 US G.), but for someone starting out in fishkeeping, you cannot go wrong with WCMMs.

A distinctive, unusual and tiny Killifish with bright blue eyes giving them their common name. Best kept in groups of at least 5 and, due to their size, best kept with other micro fish like Pygmy Corydoras. Otherwise entirely peaceful and appreciate a mild current and dense planting, will prefer a well matured tank.

Stocking Ideas

If you fancy some of the community fish suggested above, here are some ideas of what and how many you can keep together. Remember that any tank must be cycled before the addition of any fish.

Remember not to put too many fish in your 10 gallon. It can often be easy to get over excited about this hobby and want more fish then your tank can handle. For more information see Beginning Fishkeeping-Adding Fish.

Species Options

These will only really tolerate being in a tank with their own species, or indeed alone. Do plenty of research before considering to keep these animals. Many need quite specific care.

Shelldweller Cichlid

The African Butterfly Fish is a carnivorous hunter. In a larger tank it could be kept with other fish, but in a 38 Litres (10 US G.) it's best kept alone as it has a remarkably large mouth that will swallow any smaller tankmates, as well as having long finnage that can be nipped by other fish. It's also entirely top-dwelling and an excellent jumper, so a tight lid is a must. It would make a good talking point though and is quite unusual looking. It's not very active and will hang in one place, often corners, for long amounts of time, which makes it suitable for 38 Litres (10 US G.).

This shell dwelling Cichlid would be ideal for a 38 Litres (10 US G.) species tank. They grow to just under 5.1cm (2") long and need a sand substrate, with lots of empty shells. As with most African Cichlids, this shell dweller needs a reasonably high pH and prefers harder water. They must be kept in a species tank as they can be aggressive towards other fish, especially the males. They will happily breed in captivity. This is the only Cichlid we would really recommend for a tank this small.

A tiny (1" long) puffer fish that thrives in a 38 Litres (10 US G.) tank. These curious little fish are also exceptionally aggressive. In a 38 Litres (10 US G.) tank, decor should be dense planting, caves and bogwood, these fish need to be kept busy. In terms of stocking, two males should not be kept as they will fight to the death. It's generally recommended to keep 2-3 gallons per fish, so therefore in a 38 Litres (10 US G.), you can keep 2 females and 1 male. Or 3 females.

A small aquatic frog that lives its entire life in water. This species is a fun amphibian to have in a tank of this size and two or three can comfortably be kept if the tank is well filtered. They can be kept with other small fish listed on this page with notable caution. They can be out competed to food, and be injured by fish like Bettas and Gouramis nipping off their toes or breaking their legs. In return, they can latch on to the tails of slow moving fish, again like Bettas due to their poor eyesight mistaking the tails as food.

Bumblebee Goby (Brachygobius species)

A small brackish fish that can tolerate freshwater, but really is best in brackish. A small and peaceful fish that can be kept with others of it's own kind, but will be nippy towards long-finned fish and may be predated upon by anything larger. Due to it's salty needs, best kept in a species tank if kept in 38 Litres (10 US G.).

A small unusual Gourami that may be challenging to keep, but make an interesting talking point. They need exceptionally low pH (4.0-6.5) and therefore is best in a species tank with view to encouraging them to breed.

Fish NOT suitable for a 10 Gallon tank

Many common popular fish are in fact NOT suitable for this size tank. Either they are too active such as the Neon Tetra, Zebra Danio or Platy, or grow too large such as the Goldfish, Mollies, all Plecos and many of the larger Corydoras catfish. The Dwarf Gourami, despite it's common name, should really be kept in a larger tank of 57 Litres (15 US G.), and also current fish available have been sickly and it's not recommended to add these to established tanks.

Invertebrates in a 10 Gallon

Many of the inverts on sale in petstores are suitable for a 10 gallon tank, and most will not contribute much to the bioload. Beware, however, keeping the smaller shrimp such as Cherry Shrimp with fish such as Bettas as they may get mistaken as dinner!

Suitable for communities with fish

These invertebrates can be kept safely with fish in a 10 gallon.

Ghosties are peaceful scavenging shrimp, they won't put a huge dent on algae. They should be fine with smaller fish, but it must be noted that Ghost Shrimp are often used as feeder shrimp and fish such as Betta splendens and Gouramis may see them as dinner!

Amanos are larger than Ghost Shrimp, but have a more algae-based diet. Because they are larger they are less likely to be seen as food by similar sized tankmates. These Shrimp are social and do best in a trio.

Red Cherry Shrimp are an excellent choice for the 38 Litres (10 US G.) tank. The shrimp are very easy to care for once the colony is established. Given the entire tank for their species they will readily breed, however, even with fish the adults will live happily. Keep in groups of around 5 as they are sociable little shrimp.

Apple Snails are excellent tankmates for peaceful community fish in a 38 Litres (10 US G.) tank. They will eat algae, and if only one is kept, will not reproduce. It must be noted that snails add more to the bioload than that of shrimp.

Relatively new to the hobby, this tiny pale-coloured and secretive crab is a scavenger and as an adult is tiny at around 1cm (0.4"). As it is so small it will easily be chomped by larger fish, but could work with very small fish such as Ember Tetras provided the crab has plenty of hiding places. This crab is entirely aquatic, it does not need land, and is entirely freshwater also.

Suitable for species tanks only

These invertebrates can be kept in a 10 gallon, BUT do not do well with fish.

The Red Claw Crab is often marketed as an invertebrate suitable for a freshwater community tank. It is not. The Red Claw is really a brackish crab and requires a specialist set-up with both filtered water and an area for it to climb out on. If it's not provided with some access to get out of water, it will eventually die. It shouldn't be kept with other crabs as it will be territorial. It is an opportunistic feeder and may prey on any fish it can catch.