has anybody here ever kept them in a big group 30+. am thinking about getting some for my 5ft. 75 gal. long tank. they will be housed with a pair of Acarichthys Heckelii and a Blue Acara. My question is are they fin nippers?? even in a big group will they still nipp other fish? Same question for the bleeding heart. Am looking for a good size tetra that won't nipp on fins.