I'd focus about getting a larger tank before buying anymore fish..the next tank mates are iffy.
cant pick
either 2-3 grass pickel's
1-2 blue gill
orinite bichir
and some type of plant. i just dont know much about them and what is needed to keep them alive
when the fish i have get to big for the tank then they will be moved to my fathers tank. at this point 3 fish in the tank, it looks very...boring