catfish · freshwater

Glass Catfish: adult size, tank size & tankmates

The Glass Catfish (Kryptopterus vitreolus) grows to about 3.1 in (6.5 cm SL). It needs a tank at least 35 inches long and about 21 gallons. Keep at least 6 together, at 68–79°F.

How big it really gets

Drawn to scale against common tank lengths. Green bars meet the minimum tank length from our sources.

Adult: about 3.1 in · needs 35 in of tank10 gal · 20 in ✕20 long / 29 · 30 in ✕40 breeder · 36 in ✓55 / 75 gal · 48 in ✓125 gal · 72 in ✓

Will it fit your tank?

Check a full stocking list →

Quick facts

Adult size
3.1 in (6.5 cm SL)
Minimum tank
35 inches long and about 21 gallons
Temperature
68–79°F
pH
4–7
Hardness
1–10 dGH
Group size
6+
With other fish
peaceful
With its own kind
peaceful
Swims
middle of the tank
Diet
carnivore
Care level
intermediate
Lifespan
not stated in sources

Watch for: may eat baby shrimp

Glass Catfish tankmates

Checked with the same rules as our tank builder: temperature overlap, pH and hardness, predation and mouth size, fin-nipping and temperament. Tank size is left out here; check it in the builder.

Good tankmates

Use caution

Avoid

All 105 species we checked against the Glass Catfish
SpeciesVerdictWhy
African Dwarf FrogCompatibleNo conflicts found
Bala SharkCompatibleNo conflicts found
BettaCompatibleNo conflicts found
Black Neon TetraCompatibleNo conflicts found
Black Skirt TetraCompatibleNo conflicts found
Bleeding Heart TetraCompatibleNo conflicts found
Bolivian RamCompatibleNo conflicts found
Bristlenose PlecoCompatibleNo conflicts found
Bronze CoryCompatibleNo conflicts found
Buenos Aires TetraCompatibleNo conflicts found
Bumblebee GobyCompatibleNo conflicts found
Cardinal TetraCompatibleNo conflicts found
Celestial Pearl DanioCompatibleNo conflicts found
Cherry BarbCompatibleNo conflicts found
Chili RasboraCompatibleNo conflicts found
Clown KillifishCompatibleNo conflicts found
Clown LoachCompatibleNo conflicts found
Clown PlecoCompatibleNo conflicts found
Cockatoo Dwarf CichlidCompatibleNo conflicts found
Common / Comet GoldfishCompatibleNo conflicts found
Common PlecoCompatibleNo conflicts found
Congo TetraCompatibleNo conflicts found
Denison BarbCompatibleNo conflicts found
Diamond TetraCompatibleNo conflicts found
Dwarf GouramiCompatibleNo conflicts found
Dwarf Neon RainbowfishCompatibleNo conflicts found
Ember TetraCompatibleNo conflicts found
Fancy GoldfishCompatibleNo conflicts found
Giant DanioCompatibleNo conflicts found
Glowlight TetraCompatibleNo conflicts found
Gold BarbCompatibleNo conflicts found
GuppyCompatibleNo conflicts found
Harlequin RasboraCompatibleNo conflicts found
Head-and-tail-light TetraCompatibleNo conflicts found
Hillstream LoachCompatibleNo conflicts found
Honey GouramiCompatibleNo conflicts found
Japanese Trapdoor SnailCompatibleNo conflicts found
Julii CoryCompatibleNo conflicts found
KribensisCompatibleNo conflicts found
Kuhli LoachCompatibleNo conflicts found
Lambchop RasboraCompatibleNo conflicts found
Lemon TetraCompatibleNo conflicts found
Malaysian Trumpet SnailCompatibleNo conflicts found
Marbled HatchetfishCompatibleNo conflicts found
Moonlight GouramiCompatibleNo conflicts found
Neon TetraCompatibleNo conflicts found
Odessa BarbCompatibleNo conflicts found
OtocinclusCompatibleNo conflicts found
Panda CoryCompatibleNo conflicts found
Paradise FishCompatibleNo conflicts found
Pea PufferCompatibleNo conflicts found
Pearl DanioCompatibleNo conflicts found
Pearl GouramiCompatibleNo conflicts found
Penguin TetraCompatibleNo conflicts found
Peppered CoryCompatibleNo conflicts found
PlatyCompatibleNo conflicts found
Pristella TetraCompatibleNo conflicts found
Pygmy CoryCompatibleNo conflicts found
Ramshorn SnailCompatibleNo conflicts found
Rosy BarbCompatibleNo conflicts found
Rummy-nose TetraCompatibleNo conflicts found
Scissortail RasboraCompatibleNo conflicts found
Serpae TetraCompatibleNo conflicts found
Siamese Algae EaterCompatibleNo conflicts found
Silver HatchetfishCompatibleNo conflicts found
Silver Tip TetraCompatibleNo conflicts found
Sparkling GouramiCompatibleNo conflicts found
Sterbai CoryCompatibleNo conflicts found
SwordtailCompatibleNo conflicts found
Tiger BarbCompatibleNo conflicts found
Tinfoil BarbCompatibleNo conflicts found
Upside-down CatfishCompatibleNo conflicts found
Weather LoachCompatibleNo conflicts found
White Cloud Mountain MinnowCompatibleNo conflicts found
Zebra DanioCompatibleNo conflicts found
Amano ShrimpCautionGlass Catfish may eat baby Amano Shrimp. Adults are usually safe, but expect fewer shrimplets.
AngelfishCautionAngelfish can bully smaller, peaceful Glass Catfish.
Assassin SnailCautionGlass Catfish (pH 4–7) and Assassin Snail (pH 7.5–8) prefer different pH.
Bamboo ShrimpCautionGlass Catfish may eat baby Bamboo Shrimp. Adults are usually safe, but expect fewer shrimplets.
Blood Parrot CichlidCautionBlood Parrot Cichlid can bully smaller, peaceful Glass Catfish.
Cherry ShrimpCautionGlass Catfish may eat baby Cherry Shrimp. Adults are usually safe, but expect fewer shrimplets.
Crystal Red ShrimpCautionGlass Catfish may eat baby Crystal Red Shrimp. Adults are usually safe, but expect fewer shrimplets.
DiscusCautionGlass Catfish and Discus only share 79–79°F. That's a tight window.
Electric Blue AcaraCautionElectric Blue Acara can bully smaller, peaceful Glass Catfish.
Electric Yellow LabCautionElectric Yellow Lab can bully smaller, peaceful Glass Catfish.; Glass Catfish (pH 4–7) and Electric Yellow Lab (pH 7.7–8.6) prefer different pH.
Endler's LivebearerCautionGlass Catfish (1–10 dGH) and Endler's Livebearer (15–35 dGH) prefer different water hardness.
Firemouth CichlidCautionFiremouth Cichlid can bully smaller, peaceful Glass Catfish.
Forktail Blue-eyeCautionGlass Catfish (1–10 dGH) and Forktail Blue-eye (15–30 dGH) prefer different water hardness.
Ghost ShrimpCautionGlass Catfish may eat baby Ghost Shrimp. Adults are usually safe, but expect fewer shrimplets.
Kissing GouramiCautionKissing Gourami can bully smaller, peaceful Glass Catfish.
MollyCautionGlass Catfish (1–10 dGH) and Molly (15–30 dGH) prefer different water hardness.
Mystery SnailCautionGlass Catfish (pH 4–7) and Mystery Snail (pH unknown) prefer different pH.; Glass Catfish (1–10 dGH) and Mystery Snail (unknown dGH) prefer different water hardness.
Nerite SnailCautionGlass Catfish (pH 4–7) and Nerite Snail (pH 8–8.4) prefer different pH.
Pictus CatfishCautionPictus Catfish can bully smaller, peaceful Glass Catfish.
Rainbow SharkCautionRainbow Shark can bully smaller, peaceful Glass Catfish.
Red-Tail SharkCautionRed-Tail Shark can bully smaller, peaceful Glass Catfish.
Three-spot GouramiCautionThree-spot Gourami can bully smaller, peaceful Glass Catfish.
Variatus PlatyCautionGlass Catfish (1–10 dGH) and Variatus Platy (14–30 dGH) prefer different water hardness.
Yoyo LoachCautionYoyo Loach can bully smaller, peaceful Glass Catfish.
Boesemani RainbowfishAvoidGlass Catfish (68–79°F) and Boesemani Rainbowfish (81–86°F) need different temperatures.
Chinese Algae EaterAvoidChinese Algae Eater grows 4× longer than Glass Catfish and may treat it as food.; Chinese Algae Eater is aggressive toward tankmates. Glass Catfish is peaceful.
Convict CichlidAvoidConvict Cichlid is aggressive toward tankmates. Glass Catfish is peaceful.
German Blue RamAvoidGlass Catfish (68–79°F) and German Blue Ram (81–86°F) need different temperatures.
Iridescent SharkAvoidIridescent Shark eats small fish, and Glass Catfish only grows to about 3.1 in.
OscarAvoidOscar eats small fish, and Glass Catfish only grows to about 3.1 in.

Care notes

Needs: Timid - does poorly with larger or boisterous fish; must be kept in a school; offer small live or frozen foods (Artemia nauplii, Moina, grindal worms) daily alongside dried food.

Group: SF: highly gregarious, forms tight schools; a group of 6 or more is the minimum recommended.

Temperament: peaceful toward other fish, peaceful toward its own kind. Lives in the middle of the tank.

Common questions

How big does a Glass Catfish get?

About 3.1 inches (6.5 cm SL) as an adult, according to seriouslyfish.com.

What size tank does a Glass Catfish need?

At least 35 inches long and about 21 gallons. The smallest standard tank that meets that is a 40 gallon breeder.

How many Glass Catfishs should be kept together?

At least 6. SF: highly gregarious, forms tight schools; a group of 6 or more is the minimum recommended.

What fish can live with a Glass Catfish?

Species that passed every check include Neon Tetra, Cardinal Tetra, Harlequin Rasbora, Ember Tetra, Chili Rasbora, Celestial Pearl Danio.

Gear for a Glass Catfish setup

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Related guides

Sources

Values come from these pages, in our own words. Status: verified (independent spot-check). Last reviewed 2026-10-12.