Blue danio

Danio kerri

FreshwaterFish

Care at a glance

Temperature
68–79°F
20–26°C
pH
6.0–7.5
Adult size
1.8 in
4.5 cm
Minimum tank
11 gal
40 L
Temperament
Peaceful
Social behavior
Schooling
Swim level
Middle
Difficulty
Beginner
Breeding
Medium
Rarity
Rare
Family
Cyprinidae
Origin
Thailand

Overview

Keep them in a group of six or more, ideally more, since they settle down and look better in numbers. They're fast, active swimmers that hang in the upper half of the tank. Aim for around 40 liters minimum, pH from 6 to 7.5, and temperatures between 20 and 26 C. They're peaceful and easy to feed: good flake, small pellets, and frozen brine shrimp or daphnia a few times a week.

In the wild

Blue danios come from clear, gently flowing streams in Thailand and nearby parts of Southeast Asia, often over sand and rock with plants along the edges. The water there runs soft and a little acidic to neutral. Give them open swimming room up top, some current from the filter, and a temperature in the low to mid 20s C.

Good to know

This is a small cyprinid, reaching about 4 to 5 cm as an adult. It's an egg scatterer with no parental care, and eggs usually hatch in a day or so. Wild stocks are stable, though deforestation and pollution are the usual long-term concerns for stream fish like this one.

Did you know

Danio kerri was first described from Thailand's Ko Yao islands, and it's a close relative of the zebra danio. The two will sometimes hybridize in aquariums if you keep them together without enough of their own kind.

Weekly picks

Tank mates

Blue danio is a peaceful, schooling 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.

Check the full mix in the stocking calculator

Common questions

What size tank does a Blue danio need?

A Blue danio needs at least 11 gal (40 L). It spends most of its time in the middle.

What temperature and pH does a Blue danio need?

A Blue danio is comfortable at 68–79°F (20–26°C) with a pH of 6.0–7.5.

How big does a Blue danio get?

An adult Blue danio reaches about 1.8 in (4.5 cm).

Does a Blue danio need a group?

Yes. A Blue danio is a schooling species and should be kept in a group, not singly.

Related species