Minimun Tank Size For Black Ghost Knifefish?

[joyboy]

My tank is 4 foot, will it be big enough for a Black Ghost knifefish?

 

[KittyKat]

For them to achieve their full potential, I suspect that they would require around an 8*3 ft footprint tank. Personally, I would not keep this species because of its potential adult size and the fact that it reaches its full size in home aquaria only extremely rarely.

It is one of the fish that is very commonly kept in tanks which are too small, so if I absolutely needed to have one for some reason, I would not buy it from a shop to discourage it being offered for sale at all. Instead, I would try to "rescue" one from someone with a small tank.