Can kuhli loaches live with black ghost knives?

Verdict

No. Kuhli loaches and black ghost knives should not share a tank. An adult black ghost knife eats fish that fit in its mouth, and at 3.5 inches kuhli loaches do.

Kuhli loach75–86°F · pH 5.5–7

Black ghost knife73–82°F · pH 6–8

What to watch

Deal breakerAn adult black ghost knife eats fish that fit in its mouth, and at 3.5 inches kuhli loaches do.
Watch outBlack ghost knives grow to 15 inches and need 125 gallons, far more than a tank set up for kuhli loaches.

What works

Both are fine at 75–82°F.
pH 6–7 suits both.

Water side by side

The green band is the temperature range both can live in.

The green band is the pH both tolerate.

Size to scale

Adult length in an aquarium. A fish can swallow anything that fits in its mouth, roughly a third to half its own length for predators.

Care at a glance

	Kuhli loach	Black ghost knife
Temperature	75–86 °F	73–82 °F
pH	5.5–7	6–8
Adult size	3.5 in	15.0 in
Minimum tank	20 gal	125 gal
Temperament	Peaceful	Semi-aggressive
Swims at	Bottom	Bottom
Group	Groups of 6+	One per tank
Diet	Omnivore	Carnivore

Better tank mates for kuhli loaches

All kuhli loach tank mates

Better tank mates for black ghost knives

All black ghost knife tank mates

Questions

Can kuhli loaches live with black ghost knives?

No. Kuhli loaches and black ghost knives should not share a tank. An adult black ghost knife eats fish that fit in its mouth, and at 3.5 inches kuhli loaches do.

What temperature suits both kuhli loaches and black ghost knives?

75–82 °F. Kuhli loaches need 75–86 °F, black ghost knives need 73–82 °F.

What size tank do kuhli loaches and black ghost knives need together?

At least 125 gal, set by the black ghost knife. Add space for each extra fish.