Dang, that's depressing. I really like how black bar silver dollars look, but I want to get a fish that isn't scared anytime someone walks by the tank.
I have 11 SDs (7 red hooks and 4 reg) in a 180g and they seem to be ok. They still dart a bit when I walk by the tank. They by no means hurt themselves on the driftwood or glass. Maybe a few few more fish to school with and they might calm down. They school with 2 scombs too. lol