I am thinking of setting up a tang tank sometime in the near future. My experience with cichlids = angels and their aggression makes me nuts I have kept sunfish, so it's not like I've never seen an aggressive fish. Anyway, I want a tang tank. I like Cyprochromis Leptosoma and Neolomprogus Leleupi and the shellies I don't go for the shellies' color, just the shell stuff. What size tank should I look for?