I had a nem tank and broke it down 3 or 4 months ago... But i had 8 RBTA's in it (only 2 from the same place), I think at one point i had 12 GBTA's in the tank and sold most of those off, and then i put a sunburst in there and it lasted a few months and then just melted. And i had a large carpet nem and it's in my 125 gallon tank. Also had a few condy's that i didnt keep for very long, as they liked to attack the acans... Most of my nems were from various places but i believe i picked up 6 GBTA's from Brandon in Windsor and those were all splits. But i had up to 22 at one point in the tank with the biggest being a RBTA that was about 16" across. Never heard of another BTA eating another BTA though. My carpet has been through a few fish, but never another nem. Definately something to keep an eye out for now!