I don't know anything about the bicher, but I have a ropefish, shes in a 55 and only about 4.5-5 inches long. Its a good size for them, they grow slowly about an inch per year I've heard. Be prepared for you not to see it/them very often. Most of the time mine hides and I won't see it for weeks and think its dead then it just appears ¯\_(ツ)_/¯ good luck!