Black Skirt Tetra
Fish
Beastly Facts · Updated
The hardy, black-finned schooler that keeps its nipping in the family!
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Did you know? Every black skirt tetra starts out with ovaries: in fish that become males, the egg tissue breaks down and is replaced as the testes develop.
The first week
The numbers a new owner needs in the first week, each from the article it links to. Rows with no link come from the encyclopedia.
- How many
- Twelve. Kept in a group of 12 or more, they usually turn their nipping on each other instead of their tankmates.Handling guide →
- Tank size
- A 20-gallon long, 30 x 12 inches (75 x 30 cm) across the base, for a school of 12. A 10-gallon is too small.Setup guide →
- Temperature
- 68 to 79°F (20 to 26°C), which tops out below an ember or cardinal tank. They eat and move less by about 63°F, so run a heater in any cool room and never set it past 79°F.Setup guide →
- Water chemistry
- pH 6.0 to 7.5 and 5 to 19 dGH. Captive-bred stock adapts well, so tap water that tests inside both bands only needs dechlorinating.Setup guide →
- Cycle first
- Cycle the tank fully before the school goes in, then hold the water steady.Setup guide →
- Diet
- Flake or granules as the daily staple, with small live or frozen foods such as daphnia and bloodworm offered regularly.Feeding guide →
- Feeding schedule
- Once a day for adults, small enough that none of it is left lying on the bottom.Feeding guide →
- Tankmates
- They nip fins, and slow, long-finned fish take the worst of it, so no bettas. Livebearers, danios, rasboras, other tetras, Corydoras and smaller plecos suit them.Handling guide →
- Acclimation
- 30 to 60 minutes of adding tank water to the bag in small amounts with the lights off. Net the fish across and throw the bag water away.Handling guide →
- Quarantine
- At least 30 days in their own tank before new fish meet the school.Health guide →
- Ich
- Ich can kill within about two days, so treatment starts the day spots show. Heat goes only to 79°F with an air stone; aquarium salt or an ich medication does the killing.Health guide →
- Color
- Young fish carry the deepest black and turn paler as they mature. A fish that goes darker and sits apart from the school is the one to check.Health guide →
- GloFish Skirt Tetras
- The same species in the same tank, run at 76 to 79°F all year. Adult GloFish handled cold far worse than unrelated adult white skirts in one comparison, though young GloFish showed no gap against their siblings.Setup guide →
- Water changes
- 25 to 30% weekly from the substrate, with conditioned water at tank temperature. Test nitrate first: under 20 ppm the routine is right, past 40 ppm the next change is 50%.Aquarium Water Changes →
- Budget
- About $3 to $6 a fish, GloFish $12 to $13; twelve come to $35 to $75. Setup roughly $165 to $340.Cost guide →
- Lifespan
- About 3 to 5 years.Cost guide →
- Adult size
- About 2 to 2.5 inches in aquariums, up to 3 inches (7.5 cm).
- Power outage
- Oxygen is the threat, not darkness. Unplug the filter rather than letting it sit dead in the water, and keep the surface moving.Power outage guide →
Emergency card
Test the water first, then act on these today.
- Two or more fish off their food or moving slowly at the same time
- A fish found dead: take the body out of the tank before anything else
- The whole school gone sluggish and eating less: read the thermometer along with the test kit
- Fish piping at the surface or coughing: if the water tests clean, gill flukes are one cause
- White spots on the body or fins: start ich treatment today
- A fish that turns darker, keeps apart from the school and refuses food while the water tests clean
Watch and check again tomorrow.
- A torn or ragged fin on a single fish
- One fish eating less than the others but otherwise behaving normally
- A slow run of losses, one fish at a time, with no clear cause
Ich moves fast in this species, so a fish with white spots is treated the same day.
Where to go next
How Much Does Black Skirt Tetra Ownership Cost?
$3 to $6 a fish, what GloFish skirts cost, and the $165 to $340 for a 20-gallon long.
Black Skirt Tetra Tank Setup: A 20-Gallon Long, Cooler Water, and Room to Swim
A 20-gallon long for 12, a cooler 68 to 79°F range, and running a GloFish tank warmer.
Black Skirt Tetra Feeding: Diet, Food Size, and How Often to Feed
Once a day for adults, the live and frozen foods worth adding, and food for fry.
Black Skirt Tetras Nip Fins, So the School and the Tankmates Come First
Fin nipping and the school of 12 that contains it, which tankmates work, and acclimation.
Common Black Skirt Tetra Health Issues (and Why Ich Heat Stops at 79°F)
Why ich gets treated the same day, the 79°F heat limit, ragged fins and the 30-day quarantine.
Black Skirt Tetra Enrichment: A School That Moves as One
How a startled school passes the alarm faster than any one fish could, and what keeps a big school busy.
What to buy
As an Amazon Associate I earn from qualifying purchases. Underlined items are paid Amazon links, at no extra cost to you.
Prices and the reasoning behind each item are in How Much Does Black Skirt Tetra Ownership Cost?.
Full Black Skirt Tetra gear listFrequently Asked Questions
What size tank do black skirt tetras need?
A 20-gallon long, 30 x 12 inches (75 x 30 cm) across the base, for a school of 12. The length is the part that counts, because the school uses the open middle of the tank to swim.
How often should I feed black skirt tetras?
Once a day for adults. Keep the meal small enough that none of it is left lying on the bottom, because overfeeding is the usual mistake and it fouls the water.
Can black skirt tetras take the 86°F ich heat treatment?
Not as a plan. 86°F is 7°F past the 79°F top of the species' range, so the tank goes only to 79°F, with an air stone running, and aquarium salt or an ich medication kills the parasite.
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