Splash tetra
Copella arnoldi
FreshwaterFish
Care at a glance
- Temperature
- 68–82°F
- 20–28°C
- pH
- 5.5–7.0
- Adult size
- 2.2 in
- 5.5 cm
- Minimum tank
- 18 gal
- 70 L
- Temperament
- Mostly peaceful
- Social behavior
- Shoaling
- Swim level
- Middle
- Difficulty
- Easy
- Breeding
- Hard
- Rarity
- Rare
- Family
- Lebiasinidae
- Origin
- Brazil
Overview
Keep splash tetras in a group of six or more in a tank of around 70 liters, with the water level a bit lower so there is air space above. They hang near the surface and are mostly peaceful. In the wild they eat insects and larvae, so feed floating flakes, small pellets, and surface foods like daphnia and mosquito larvae. Soft, acidic, warm water suits them best.
In the wild
Splash tetras live in shallow, slow water in the Amazon and Orinoco basins, including small streams and flooded forest with leaf litter and surface plants. The water is clear, soft, and slightly acidic. Give them a calm, well-planted tank with floating cover, soft acidic water, and a temperature anywhere from the low 20s to high 20s C. A tight lid matters because they spend time right at the surface and will jump.
Good to know
Copella arnoldi sits in the family Lebiasinidae, the pencilfish family, and reaches about 5.5 cm. It is best known for spawning out of the water, which is rare among fish. The eggs are laid on a leaf or surface above the waterline. It is a widely available species with stable wild populations.
Did you know
A spawning pair leaps out of the water together and presses against an overhanging leaf, where the female lays eggs above the waterline. The male then stays below and flicks water up with his tail to keep the eggs wet until they hatch, which keeps them safe from underwater predators.
Weekly picks
Tank mates
Splash tetra is a mostly peaceful, shoaling species that keeps to the middle. These picks share a community profile with it, are safe together in both directions, and overlap on water type, temperature and pH.

Marble wood shrimp
Atya scabra
Freshwater3.9 in (10 cm) · 20 gal (75 L)73–82°F (23–28°C)
Common spiny loach
Lepidocephalichthys thermalis
Freshwater3.1 in (8 cm) · 20 gal (75 L)72–82°F (22–28°C)
Blue panchax
Aplocheilus panchax
Freshwater3.5 in (9 cm) · 20 gal (75 L)72–82°F (22–28°C)
Panda dwarf cichlid
Apistogramma nijsseni
Freshwater3.3 in (8.5 cm) · 18 gal (70 L)75–82°F (24–28°C)
Bronze cory
Osteogaster aenea
Freshwater3 in (7.5 cm) · 20 gal (75 L)70–81°F (21–27°C)
Six-barred panchax
Epiplatys sexfasciatus
Freshwater3.9 in (10 cm) · 20 gal (75 L)72–81°F (22–27°C)
Common questions
What size tank does a Splash tetra need?
A Splash tetra needs at least 18 gal (70 L). It spends most of its time in the middle.
What temperature and pH does a Splash tetra need?
A Splash tetra is comfortable at 68–82°F (20–28°C) with a pH of 5.5–7.0.
How big does a Splash tetra get?
An adult Splash tetra reaches about 2.2 in (5.5 cm).
Does a Splash tetra need a group?
Yes. A Splash tetra is a shoaling species and should be kept in a group, not singly.
Related species
2 in (5 cm)16 gal (60 L)75–82°F (24–28°C)Spotted splash tetra
Copella nattereri
2 in (5 cm) · 16 gal (60 L)
2.2 in (5.5 cm)16 gal (60 L)73–82°F (23–28°C)Harrison's pencilfish
Nannostomus harrisoni
2.2 in (5.5 cm) · 16 gal (60 L)
2.4 in (6 cm)18 gal (70 L)70–81°F (21–27°C)Golden pencilfish
Nannostomus beckfordi
2.4 in (6 cm) · 18 gal (70 L)
2 in (5 cm)14 gal (54 L)73–81°F (23–27°C)Marilyn's pencilfish
Nannostomus marilynae
2 in (5 cm) · 14 gal (54 L)
3.9 in (10 cm)32 gal (120 L)73–82°F (23–28°C)Red-spotted tetra
Copeina guttata
3.9 in (10 cm) · 32 gal (120 L)
1.2 in (3 cm)20 gal (75 L)75–82°F (24–28°C)Purple pencilfish
Nannostomus rubrocaudatus
1.2 in (3 cm) · 20 gal (75 L)
