I have Darters of all types, killies, stone rollers and other miscellaneous minnows. The crayfish(in a separate tank) are fun to watch. I placed rocks all over so they can dig dens to sleep in. I also have a tank of catfish of all types. It's neat to watch my blind channel. He has absolutely no problem finding food. I read that catfish can sense/taste??? Food thru their skin besides just their whiskers. I'll try to find the article.
30 long, 35 octagon, 55, a planted 20 and I'm working on a bigger one. I do catch them myself. I use a dip net and an umbrella net. The umbrella works a lot like it sounds.