What size tank is best?

[benzjamin13]

I wish a lot of the lfs around here were like that. They just want money

 

[joeytoe]

Ive had clown knives in a 55gal, 75gal, an currently I have one in my 120gal. there nice fish, graceful Ambush hunters (when live food is provided) they can be skiddish at times or pricks. Ive seen mine attack my marble cat (which could easily kill him) an cause him to swim away.

I wouldnt suggest any tank under 120gallons though they need room to swim.