Two questions

[misstephaniexxx]

I have room for a couple more fish in my tank (i have a male betta, and 4 cardinal tetras)
what kind of fish should I add?

and second, my aunt said I should get a goby (specifically a knight goby)
... i dont know anything about them? are they aggressive? how big do they get? do they go well with bettas and tetras?

[ChristinaRoss]

since they can grow to 3" and eat smaller fish i wouldnt recommend them with neons in there.

id recommend some otos, their cute, small and will help in being the clean up crew