Trumpet knifefish??

[Bret11]

How big do trumpet knifefish get and are they aggressive?

 

[kno4te]

Seen an 18in a while ago. Peaceful and similar to bgk. No aggressive tankmates. Better in groups but need a large tank.

 

[Bret11]

Seen an 18in a while ago. Peaceful and similar to bgk. No aggressive tankmates. Better in groups but need a large tank.

What’s the minimum tank size for them?

 

[Audaxcity]

IME, knives don't use as much space as most fish their size, but I'd say an absolute minimum of 125g long term just because apparently trumpets get pretty big.

 

[kno4te]

I’d say a 180 lifelong. As it should be able to hit the 20in mark.

 

[blackbullhead]

Depends on what you mean by trumpet knifefish...some species of Rhamphichthys grow to 3 ft. They can be aggressive toward each other, but they really can't do much damage as they don't have any teeth.