stocking 45 gallon

Hello, I just got a 45-gallon tank. I wonder what to do with it, as the original idea was shell-dwellers, but that was decided when I thought I was getting a 30 or 35, not a 45. I currently have a 30-gallon long nano community, a 10-gallon block Black Tiger Dario/Badis tank, an 80-gallon high...