While I was gone for 3 days on a business trip I added two tinfoil barbs around 6" just at dithers since I removed my blackberry silver dollar and datnoid. When I came back I had to do an emergency water change.. Both of them got killed and eaten to only 1/3 of the body floating at the surface. Netted them out and fed to the feral cats around the neighborhood. I thought the tinfoils would be ok since I had my blackberries in there that were similar size.. But nope, just became big feeders real quick.