since I just switched my old 60l to sand and will be getting 6-7 pygmy cories in a few weeks, and I'am now looking to use my other 60l as a single species tank, are the any fish that would like to just be in a group by themselves, dont want tetras our cories schools as will have them in my other 60l communitys are there any rams our other biggish fish that would do well, dont want plecs either as they poop to much for my likein, so are there any rams, cichlids, killifish, our barbs that like to be in groups and would fit in a 60l? thanks for any suggestions