Stocking: Corner Tanks

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Pterophyllum scalare
Jul 22, 2006
Real Name
Against standard, rectangular tanks, corner tanks are distinctly different. They differ in shape, filtration needs, and most notably, stocking. Corner tanks themselves can differ in shape, but bowfront corner tanks are the most common. Triangular tanks and pentagon tanks, are also available and will be covered here.

Common bowfront corner tanks include the 5 gallon Corner Eclipse tank, and 36, 54, 72, and 92 gallon tanks. Pentagonal tanks include 30 and 50 gallon tanks. Finally, Triangular tanks will be represented here by 40 and 60 gallon tanks. Each tank will be given a series of stocking lists. That said, since many of these tanks are very similar in size, most notably the 54 gallon bowfront and the 50 gallon pentagonal, some of the stocking lists can be interchanged between the tanks. If information is needed on a particular species, refer to my other stocking articles as well as this site. Fish that are not listed together may or may not be compatible with one another, more likely not. Feel free to ask questions in the Freshwater Forums.

As with standard tanks, the inch per gallon rule does not apply in the least.
Always cycle your tank before adding fish, preferably through fishless cycling.
This article is designed to be a companion article to the "standard tank" articles.

Bowfront Corner Tanks
5, 36, 54, 72, and 92 gallons
This category of tanks varies greatly in size, but these are the most common sizes available. The 5 gallon bowfront corner tank is usually an Eclipse tank, with contained filtration and lighting. The others are usually free-reign tanks where the hobbyist is able to choose their own equipment.

5 gallon-5 gallon Eclipse tanks have a variety of stockings available, but none too extravagant.

Stocking 1
1 dwarf gourami- Charming fish available in a few colors of a combination of blue and red, these fish pack a large personality into a compact fish. NOTE: the recent offerings of dwarf gouramis have been notoriously weak. Try fish from singly owned LFS's or local breeders before going to chain stores.

Stocking 2
1 betta- Lots of personality, and even more colors and finnage forms, bettas are great fish for small 5 gallon corner tanks. Very hardy.

36 gallon
- Much more space than a 5 gallon corner tank, the 36 gallon corner is a great place to start and has many different stocking options to choose from.

Stocking 1
1 pair of bolivian rams- These dwarf cichlids appreciate good water quality and will reach 3 inches long.
6 lemon tetras- Yellow, nearly see-through tetras that reach 1½-2 inches long. Keep them in schools. Note that other species of tetras follow a similar profile except otherwise noted.
4 peppered corydoras- Corydoras like to be in groups, as they are very social. Being peaceful, they also make pretty good tankmates for most other peaceful fish. They reach 3 inches long. Note that all other corydoras species follow a similar profile, except the factor of length.

Stocking 2
1 male and 2 female Calvus cichlids- Piscivores, or fish eaters, calvus cichlids get to 4 inches and are a great choice for a species tank. Provide plenty of rockwork and good filtration.

Stocking 3
1 pearl gourami- Similar to dwarf gouramis, but larger and more angular in shape. They are generally peaceful, but males can be territorial toward one another.
10 cardinal tetras- Similar to neons, but get a fraction of an inch larger
4 kuhli loaches- 4 inch, snake-like fish, kuhli loaches are peaceful and like to be in groups.

54 gallon- Larger yet, this corner bowfront opens up many new possibilities.

Stocking 1
1 pair of Krib cichlids-These cichlids are much like rams in that they are usually peaceful, but they are very aggressive when breeding. They reach about 5 inches and occupy the bottom areas of the tank.
8 black skirt tetras
4 bronze corydoras

Stocking 2
12 glass catfish- Their name implies their look; glass catfish are entirely see-through. Keep them in big groups, as those that are kept singly will pine away. Keep them only with the most peaceful tankmates.
5 bronze corydoras

Stocking 3
6 marbled hatchetfish

12 neon tetras
6 pygmy corydoras

Stocking 4
1 angelfish- These cichlids easily reach 6 inches long and are available in many different color and finnage forms. Don't keep them with neons, cardinals guppies, or otos though, as they will easily be gobbled up.
10 lemon tetras
5 Schwartz's corydoras

72 gallon-
Bigger and more active fish besides bread-and-butter community fish make their appearances...

Stocking 1
6 threadfin rainbowfish- While they may not be very big, threadfin 'bows will use up every inch of the corner tank. Keep them in schools to see the best colors and activity. 2 inches is an average length, but feed them small foods- they have very small mouths and throats.
6 Striata loaches- Active, boisterous, and gregarious, these loaches like to be in groups. Dont keep them with slow moving fish, but they will still fit in a Southeastern Asian biotope perfectly.
18 harlequin rasboras

Stocking 2
6 giant danios- As active as active can be, these fish dont sit still for anyone. They'll grow to 4 inches long and are pretty hardy. Dont keep them with slow moving fish, but they do make good dither fish for larger cichlids.
12 tiger barbs- Nippy and these small barbs with tiger stripes should be kept in large schools to prevent fin nipping.
6 kuhli loaches

Stocking 3
1 firemouth cichlid- These medium-sized cichlids can be territorial, so only keep them with tougher fish such as danios, barbs, and some tetras. 4 inches is a good size, and give them plenty of space.
12 black skirt tetras
6 zebra danios

92 gallon- An "almost" big tank that can hold a variety of "monster" fish...

Stocking 1
1 Jack Dempsey Cichlid- Keep them along in a 92 corner, since space is limited. A JD will easily reach 10 inches long, and they can be aggressive.

Stocking 2
1 gold severum- These large cichlids are the near opposite of oscars; they are relatively peaceful, but can still hold their own if put with other South or Central American cichlids. They reach 8 inches long, and don't keep them with any fish that is small enough to be eaten.
6 flagtail catfish- Relatives to corydoras, these fish will reach 6 inches and swim around the middle of the tank, returning to the bottom to feed.
8 congo tetras- Some of the largest tetras, these will easily reach 4 inches long.

Stocking 3
8 Bosemani Rainbowfish- Being blue and yellow, bosemanis attractive finds. They will easily top 4 inches, usually reaching 6. Keep them in nice big schools to see the best colors.
6 angelicus loaches- Active and gregarious, angelicus loaches are a great addition to any Southeastern Asian biotope.
1 male and 2 female pearl gouramis

Pentagonal Corner Tanks
30 and 50 gallons
These tanks provide a bit more surface area than bowfronts because of their rectangualr-like frotns rather than the curved bow of the bowfront corner tanks. Stocking is similar, but a bit more forgiving.

30 gallon- A perfect choise for those who wish to have a nice sized tank in a small space.

Stocking 1
12 neon tetras
4 pygmy corydoras
12 cherry shrimp- Interesting little inverts that breed like mad. Keep them with fish that wont eat them...too quickly.

Stocking 2
4 platies
6 ember tetras
4 panda corydoras

Stocking 3

1 angelfish
1 dwarf gourami
10 red eye tetras
4 Juhli corydoras

50 gallon- Larger than a 30 gallon, a 50 gallon pentagon allows for a larger number of species to coexsist.

Stocking 1
1 angelfish
12 diamond tetras
4 porthole catfish

Stocking 2
6 Celestial Pearl Danios- Tiny danios that barely reach 1½ inch long. Great additions to a "small fish" tank. Active little fish that like to be in schools. If you feed them enough live foods and keep the water quality pristiene, they may even spawn.
18 cardinal tetras
8 pygmy corydoras

Stocking 3
1 Keyhole cichlid- Peaceful, 4-inch cichlids that have similar dispositions to rams. Each side is graced with the outline of a keyhole, which gives these cichlids their name.
12 diamond tetras
5 panda corydoras

Triangular Corner Tanks

40 and 60 gallons
These tanks are less common than their bowfront and pentagon counterparts. These tanks have even less surface area than the others because instead of having the front panel(s) come outward, the front of the tank is just a flat panel. Form sometimes takes place over function.

40 gallon- A decent ammount of space in an interestingly shaped tank

Stocking 1
1 pair of Apistogramma agassizi- These dwarf cichlids can be hard to find, but are very rewarding to keep. They are generally peacful, but they can be territorial when breeding. Pristene water conditions are appreciated, and feed them sinking foods with plenty variety.
12 black neon tetras

Stocking 2
1 Giant gourami (Colisa fasciata)- These medium-sized gouramis are essentially a larger version of dwarf gouramis, all of the color included. 4-5 inches is not an uncommon size, but keep one per tank. Dont confuse them with the other gourami commonly called "giant"- they grow to over a foot long, and quickly.
10 harlequin rasboras
5 kuhli loaches

Stocking 3
1 male and 2 female swardtails- Relatives of platies, these livebearers will reach 4 inches long and are a bit nippier than platies. Males develop an extension to their lower tail fin, hense the name "swordtail". Keep them in a ration of one male to at least two females.
8 black skirt tetras
4 bronze corydoras

60 gallon- A good balance of space and pure looks.

Stocking 1
1 angelfish
8 diamond tetras
6 marbled hatchetfish
4 peppered corydoras

Stocking 2
1 angelfish
1 festivum
1 keyhole cichlid
5 pothole catfish

Stocking 3
6 threadfin rainbowfish
18 neon tetras
6 panda corydoras

If you have any questions, suggestions, or comments, feel free to ask!

Good luck with your tank!

- Jon

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