im not sure if the tank is the same as a us ten gallon, but id say two. you could even turn it into their breeding tank, if u get a male and female. Things to mix in could be neon tetras, thats all im sure about. anyone else know?
Too small i'm afraid, you might get away with 1 on its own. Kribs are aggressive and adding any other fish to a tank that side would cause serious problems. To be honest I wouldn't add any to a tank that size. Sorry!