Is my tank adequate enough for a small group of Metynnis Fasciatus? It's 60.5" long, 16.5" wide, 25.5" tall. If so, how many? They would be with 6 Geophagus Sveni that are now juvies at 2-3", but will be about 6-7" average at full grown. I want to make sure they have adequate space in a tank just a hair over 5 feet. Thanks.