Zebra Danio Care Guide
Danio rerio
Key Takeaways
- Zebra Danio needs at least 10 gallons, with 20 gallons preferred.
- Keep water between 18-25°C and pH 6.5-7.5.
- Keep a group of at least 6 to reduce stress.
Actionable Setup Plan
- Use a longer 20-gallon aquarium when possible; their constant horizontal swimming uses space quickly.
- Keep 6+ zebra danios, use a secure lid, and leave an open swimming lane between planted areas.
- Choose cool-to-moderate-temperature tank mates that can match their activity level.
Quick Facts
Size
Adults reach about 5 cm (2 in). Plan the aquarium around a whole school’s active swimming space, not one fish’s body length.
Lifespan
A typical lifespan is 3-5 years when the school has stable water, a varied diet, and room to swim.
Minimum School Size
Keep at least 6. A larger group is usually calmer and spreads their fast, social behaviour across the school.
Care Overview
Zebra danios (Danio rerio) are hardy, fast-moving schooling fish for a cool-to-moderate-temperature freshwater aquarium. They grow to about 5 cm (2 in), usually live 3-5 years, and are best kept in a group of at least six rather than as a single fish.
Ideal Tank Setup
A 10-gallon tank is a minimum, but a longer 20-gallon tank gives an active zebra danio school much better swimming room. Use a secure lid because they jump, keep the water around 18-25°C, provide open flow-through swimming space, and keep at least six together.
Food
Zebra danios are omnivores. Feed a varied diet of quality small flakes or micro-pellets, with occasional frozen or live foods such as daphnia, brine shrimp, or bloodworms. Offer only what the school can finish quickly once or twice a day; uneaten food quickly degrades water quality.
Tank Mates
- Other danios
- Other similarly active, cool-water-compatible schooling fish
- Corydoras with compatible temperature needs
- White cloud minnows
Fish to Avoid
- Slow, long-finned fish (they may nip)
- Large aggressive fish
Common Problems
- Jumping out of uncovered tanks
- Fin nipping
Common Beginner Mistakes
- Using a tank smaller than 10 gallons, which makes water quality harder to keep stable.
- Ignoring adult size, group size, or temperament when choosing tank mates.
- Changing too much water or filter media at once before checking ammonia and nitrite.
Frequently Asked Questions
Do zebra danios need a school?
Yes. Keep at least 6 together. They are schooling fish and will be stressed and may nip other fish if kept in smaller groups.
How big do zebra danios get?
Adult zebra danios are usually about 5 cm (2 in) long. Their small size does not mean they suit a tiny aquarium: they are active horizontal swimmers and need room for a school.
How long do zebra danios live?
Zebra danios commonly live about 3-5 years with stable water quality, an appropriate group, and a varied diet.
What do zebra danios eat?
They eat small flakes, micro-pellets, and appropriately sized frozen or live foods. Feed small portions and remove excess food rather than relying on a single food type.
What are good zebra danio tank mates?
Choose peaceful, active fish with compatible cool-to-moderate water needs, such as another zebra danio school or white cloud minnows in a suitably sized tank. Avoid slow, long-finned fish and large predators.
Related Tools
Sources and Review Process
- Freshwater aquarium husbandry references for water quality, tank size, and stocking guidance.
- Species profiles and compatibility rules maintained in the AquaScience AI data set.
- Aquarium health guidance is educational and should not replace an aquatic veterinarian for severe symptoms.
More Zebra Danio Guides
A possible pairing that needs dense shrimp cover and observation.
A cool-water schooling combination with room for both groups.
Compatibility verdict: possible (70/100).
Compatibility verdict: good (88/100).