Photo: Stephen Ward · CC BY-SA 2.0
Freshwater · Beginner · 10+ gal
Danio rerio
By Fishy Dave
Zebra danios are hardy, fast-swimming beginners that want a school of six or more. Ten gallons is a tight floor. A 20-gallon long gives them the horizontal lane they actually use.
| Water type | Freshwater |
|---|---|
| Care level | Beginner |
| Minimum tank | 10 gallons |
| Temperament | Active, peaceful schooler. Keep six or more. They stay mid-to-upper water and rarely bother calm tank mates, though they may nip slow, long-finned fish if bored or understocked. |
| Diet | Omnivore. Quality tropical flakes as a staple, plus small frozen or live foods (brine shrimp, daphnia, bloodworms). Feed small portions they finish in a couple of minutes. |
| Temperature | 64–75 °F |
| pH | 6.5–7.5 |
| Hardness / salinity | Soft to moderately hard (about 5–16 dGH). They handle a wide range if changes are slow; cooler, stable water matters more than a perfect number. |
Danio rerio is a South Asian minnow that races along the length of a tank, not up and down a tall hex. Adults land around 2 inches. Six fish is a starting school; fewer and they get twitchy and may pick on quieter tank mates.
Ten gallons can hold a small group if filtration and water changes stay honest. A 20-gallon long is the kinder home. Same gallon count as a tall 20, more swimming lane, less bouncing off glass.
They sit happily in the mid-60s to mid-70s F. Rooms that stay cool often need little or no heat. That is the opposite of a guppy or betta pitch. If winter nights drop the tank below about 64 F, a modest heater keeps the floor under them.
They jump. A tight lid with no open filter cutouts is part of keeping them, not an afterthought. Cover the rim before you decorate.
Flakes work if they finish the portion. Rotate in frozen or live foods a few times a week so the school stays bright and busy. Overfeeding is how a hardy tank goes cloudy.
They make good dither fish for a peaceful community. Pair them with other active midwater fish or a cory group on sand. Skip pairing a lonely pair of danios with a long-finned show guppy and hoping for the best.
A few listings we would open for this species. Skip anything you already own that still works.
H2Pro 30-inch glass canopy for 20-long / 29-gallon tanks
Zebra danios jump. A tempered glass canopy sized for a 30-by-12 footprint (the usual 20-long opening) with a cuttable rear strip is the lid listing we would open first.
Measure the opening to the millimeter. Skip this if your tank is not a standard 20-long or 29. Cover filter and heater gaps. That is how they leave.
See this listingTetraMin Tropical Flakes, 7.06 oz
They are midwater omnivores that will actually eat a basic tropical flake. Small portions they finish in a couple of minutes beat a blizzard on the gravel.
Add frozen brine or bloodworms a few times a week. Skip this if you already feed a quality flake or micro pellet they clean up. Leftover flake is how tanks crash.
See this listingAqueon glass 20-gallon long aquarium
They swim the length of the tank. A 20-long (about 30 by 12 by 12) is the footprint that matches that habit better than a tall hex or a crowded 10.
Tank only. You still need a filter, lid, and a cycle. Skip a new tank if you already have a long 20 with open midwater. Confirm 20 Long on the listing, not a 20 High.
See this listingSix or more. A real school looks better and spreads any nipping among their own kind instead of at tank mates.
Ten gallons is a tight floor for a small group. A 20-gallon long is the honest home because they swim horizontally.
GloFish danios are genetically modified Danio rerio sold in fluorescent colors. Care is the same: school, lid, and swimming length. This page is about the classic striped fish.
Next step
Plan on 10 gallons or more. Put your actual tank size into the stocking calculator and it shows what else can live alongside them.
Open the stocking calculatorBefore you buy
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