Black ghost knife tank mates

Good matches

11 of 98

The safest picks for black ghost knives are oscars, bala sharks and kissing gouramis. Each match shares black ghost knives' temperature and pH and leaves them alone.

Nocturnal and grows long. Eats small fish at night.

Temperature

73–82°F

pH

6–8

Temperament

Semi-aggressive

Minimum tank

125 gal

With care

6

Avoid

81

Good tank mates

• Oscar74–81°F
• Bala shark73–82°F
• Kissing gourami73–82°F
• Severum74–82°F
• Bichir73–82°F
• Elephant nose fish73–82°F
• Koi73–77°F
• Common pleco73–82°F
• Tinfoil barb73–80°F
• Chinese algae eater74–80°F
• Clown loach77–82°F

Possible, with care

• Jack Dempsey Jack dempseys are aggressive. Black ghost knives hold their own only in a big tank with places to hide.
• Mystery snail Large black ghost knives crack or pick at small snails. A big mystery snail has better odds than a ramshorn.
• Flowerhorn Flowerhorns are aggressive. Black ghost knives hold their own only in a big tank with places to hide.
• Ramshorn snail Large black ghost knives crack or pick at small snails. A big mystery snail has better odds than a ramshorn.
• Nerite snail Large black ghost knives crack or pick at small snails. A big mystery snail has better odds than a ramshorn.
• Assassin snail Large black ghost knives crack or pick at small snails. A big mystery snail has better odds than a ramshorn.

Avoid

• Betta An adult black ghost knife eats fish that fit in its mouth, and at 2.5 inches bettas do.
• Axolotl Axolotls are coldwater animals (60–66°F); black ghost knives need 73–82°F. No temperature suits both.
• Pea puffer An adult black ghost knife eats fish that fit in its mouth, and at 1 inches pea puffers do.
• Angelfish An adult black ghost knife eats fish that fit in its mouth, and at 6 inches angelfish do.
• Guppy An adult black ghost knife eats fish that fit in its mouth, and at 2 inches guppies do.
• Honey gourami An adult black ghost knife eats fish that fit in its mouth, and at 2 inches honey gouramis do.
• Goldfish Goldfish are coldwater animals (60–74°F); black ghost knives need 73–82°F. They overlap only at 73–74°F, the edge of both ranges.
• Tiger barb An adult black ghost knife eats fish that fit in its mouth, and at 3 inches tiger barbs do.
• Congo tetra An adult black ghost knife eats fish that fit in its mouth, and at 3 inches congo tetras do.
• Sparkling gourami An adult black ghost knife eats fish that fit in its mouth, and at 1.5 inches sparkling gouramis do.
• Blue gourami An adult black ghost knife eats fish that fit in its mouth, and at 5 inches blue gouramis do.
• Cherry barb An adult black ghost knife eats fish that fit in its mouth, and at 2 inches cherry barbs do.
• Dwarf gourami An adult black ghost knife eats fish that fit in its mouth, and at 3 inches dwarf gouramis do.
• Lemon tetra An adult black ghost knife eats fish that fit in its mouth, and at 2 inches lemon tetras do.
• Ember tetra An adult black ghost knife eats fish that fit in its mouth, and at 0.8 inches ember tetras do.
• Black neon tetra An adult black ghost knife eats fish that fit in its mouth, and at 1.5 inches black neon tetras do.
• Neon tetra An adult black ghost knife eats fish that fit in its mouth, and at 1.5 inches neon tetras do.
• Kuhli loach An adult black ghost knife eats fish that fit in its mouth, and at 3.5 inches kuhli loaches do.
• Electric blue acara An adult black ghost knife eats fish that fit in its mouth, and at 6 inches electric blue acaras do.
• Black skirt tetra An adult black ghost knife eats fish that fit in its mouth, and at 2.5 inches black skirt tetras do.
• Harlequin rasbora An adult black ghost knife eats fish that fit in its mouth, and at 2 inches harlequin rasboras do.
• Cherry shrimp Black ghost knives hunt shrimp. Adult cherry shrimp will be eaten.
• GloFish tetra An adult black ghost knife eats fish that fit in its mouth, and at 2.5 inches glofish do.
• Pencilfish An adult black ghost knife eats fish that fit in its mouth, and at 2 inches pencilfish do.
• Pearl gourami An adult black ghost knife eats fish that fit in its mouth, and at 5 inches pearl gouramis do.
• Corydoras An adult black ghost knife eats fish that fit in its mouth, and at 2.5 inches corydoras do.
• Paradise fish An adult black ghost knife eats fish that fit in its mouth, and at 3.5 inches paradise fish do.
• Endler's livebearer An adult black ghost knife eats fish that fit in its mouth, and at 1 inches endlers do.
• Convict cichlid An adult black ghost knife eats fish that fit in its mouth, and at 5 inches convict cichlids do.
• Serpae tetra An adult black ghost knife eats fish that fit in its mouth, and at 1.75 inches serpae tetras do.
• Odessa barb An adult black ghost knife eats fish that fit in its mouth, and at 3 inches odessa barbs do.
• Platy An adult black ghost knife eats fish that fit in its mouth, and at 2.5 inches platies do.
• Molly An adult black ghost knife eats fish that fit in its mouth, and at 4 inches mollies do.
• Silver dollar An adult black ghost knife eats fish that fit in its mouth, and at 6 inches silver dollars do.
• Glowlight tetra An adult black ghost knife eats fish that fit in its mouth, and at 1.5 inches glowlight tetras do.
• Ghost shrimp Black ghost knives hunt shrimp. Adult ghost shrimp will be eaten.
• Hatchetfish An adult black ghost knife eats fish that fit in its mouth, and at 1.5 inches hatchetfish do.
• Rummy nose tetra An adult black ghost knife eats fish that fit in its mouth, and at 2 inches rummy nose tetras do.
• Yoyo loach An adult black ghost knife eats fish that fit in its mouth, and at 5 inches yoyo loaches do.
• Chili rasbora An adult black ghost knife eats fish that fit in its mouth, and at 0.8 inches chili rasboras do.
• Silver arowana An adult silver arowana eats fish that fit in its mouth, and at 15 inches black ghost knives do.
• Pygmy cory An adult black ghost knife eats fish that fit in its mouth, and at 1 inches pygmy corys do.
• Boesemani rainbowfish An adult black ghost knife eats fish that fit in its mouth, and at 4 inches boesemani rainbowfish do.
• Bristlenose pleco An adult black ghost knife eats fish that fit in its mouth, and at 5 inches bristlenose plecos do.
• Firemouth cichlid An adult black ghost knife eats fish that fit in its mouth, and at 6 inches firemouth cichlids do.
• Zebra danio An adult black ghost knife eats fish that fit in its mouth, and at 2 inches zebra danios do.
• Celestial pearl danio An adult black ghost knife eats fish that fit in its mouth, and at 1 inches celestial pearl danios do.
• Pictus catfish An adult black ghost knife eats fish that fit in its mouth, and at 5 inches pictus catfish do.
• African dwarf frog An adult black ghost knife eats fish that fit in its mouth, and at 2.5 inches african dwarf frogs do.
• Dwarf neon rainbowfish An adult black ghost knife eats fish that fit in its mouth, and at 2.5 inches dwarf neon rainbowfish do.
• Swordtail An adult black ghost knife eats fish that fit in its mouth, and at 5 inches swordtails do.
• Blood parrot An adult black ghost knife is twice the size of a blood parrot and will hunt or batter a slow, long-finned fish like this.
• Cardinal tetra An adult black ghost knife eats fish that fit in its mouth, and at 2 inches cardinal tetras do.
• Rainbow shark An adult black ghost knife eats fish that fit in its mouth, and at 6 inches rainbow sharks do.
• Rosy barb An adult black ghost knife eats fish that fit in its mouth, and at 4 inches rosy barbs do.
• Bolivian ram An adult black ghost knife eats fish that fit in its mouth, and at 3 inches bolivian rams do.
• Otocinclus An adult black ghost knife eats fish that fit in its mouth, and at 2 inches otocinclus do.
• Clown pleco An adult black ghost knife eats fish that fit in its mouth, and at 3.5 inches clown plecos do.
• African cichlid An adult black ghost knife eats fish that fit in its mouth, and at 5 inches african cichlids do.
• Glass catfish An adult black ghost knife eats fish that fit in its mouth, and at 3 inches glass catfish do.
• Bamboo shrimp Black ghost knives hunt shrimp. Adult bamboo shrimp will be eaten.
• Amano shrimp Black ghost knives hunt shrimp. Adult amano shrimp will be eaten.
• Upside down catfish An adult black ghost knife eats fish that fit in its mouth, and at 4 inches upside down catfish do.
• Red tail shark An adult black ghost knife eats fish that fit in its mouth, and at 5 inches red tail sharks do.
• Crayfish An adult black ghost knife eats fish that fit in its mouth, and at 5 inches crayfish do.
• Zebra loach An adult black ghost knife eats fish that fit in its mouth, and at 3.5 inches zebra loaches do.
• Kribensis An adult black ghost knife eats fish that fit in its mouth, and at 4 inches kribensis do.
• Killifish An adult black ghost knife eats fish that fit in its mouth, and at 2.5 inches killifish do.
• Apistogramma An adult black ghost knife eats fish that fit in its mouth, and at 3 inches apistogramma do.
• Discus An adult black ghost knife eats fish that fit in its mouth, and at 6 inches discus do.
• Electric yellow cichlid An adult black ghost knife eats fish that fit in its mouth, and at 4 inches yellow labs do.
• Gold barb An adult black ghost knife eats fish that fit in its mouth, and at 3 inches gold barbs do.
• Peacock cichlid An adult black ghost knife eats fish that fit in its mouth, and at 6 inches peacock cichlids do.
• Panda cory An adult black ghost knife eats fish that fit in its mouth, and at 2 inches panda corys do.
• Dojo loach An adult black ghost knife eats fish that fit in its mouth, and at 6 inches dojo loaches do.
• White cloud minnow White cloud minnows are coldwater animals (60–72°F); black ghost knives need 73–82°F. No temperature suits both.
• Fancy goldfish Fancy goldfish are coldwater animals (65–74°F); black ghost knives need 73–82°F. They overlap only at 73–74°F, the edge of both ranges.
• Siamese algae eater An adult black ghost knife eats fish that fit in its mouth, and at 6 inches siamese algae eaters do.
• Zebra pleco An adult black ghost knife eats fish that fit in its mouth, and at 3.5 inches zebra plecos do.
• Hillstream loach An adult black ghost knife eats fish that fit in its mouth, and at 2.5 inches hillstream loaches do.
• German blue ram An adult black ghost knife eats fish that fit in its mouth, and at 2.5 inches rams do.

Planning a mixed tank? The tank mate checker tests every pair at once. Or read the black ghost knife care sheet.