room

Hello.  I have 4 African banned barbs, 4 zebra danios, a 3 inch redtail, 2 silver tipped tetras, and 1 dwarf pleco.  I have a 30 gallon tank that's in very good shape.    All fish are healthy.  I need advice though.  My tank, though active, visually looks a tad empty.  My question is, given the...