Glass knifefish vs Freshwater butterflyfish: can they live together?

Verdict: Not recommended

  • The Freshwater butterflyfish is aggressive towards other fish.
  • The Glass knifefish is best kept in a species tank.
  • The Glass knifefish is aggressive towards other fish.
  • An adult Glass knifefish is about 3 times the length of a Freshwater butterflyfish and may eat it.
  • Both are comfortable at 24–28°C (75–82°F).
  • A pH of 6.7–7.5 suits both.

Side by side

Glass knifefishFreshwater butterflyfish
Adult size35 cm (14 in)11 cm (4.3 in)
Minimum tank210 L (55 US gal)75 L (20 US gal)
Temperature23–28°C (73–82°F)24–30°C (75–86°F)
pH6.0–7.56.7–7.5
Hardness2–15 dGH (36–268 ppm)2–10 dGH (36–178 ppm)
TemperamentAggressiveAggressive
Community tankNot suitable–
Care levelDifficult–
DietCarnivoreCarnivore

Species profiles