Ember tetras and very good community fish, they are small less then an inch when fully grown and tend to stick together most of the time. I hope to add to my small shoal of them and possibly moved them to a 30 gallon tank with other small fish like the rosboras in the future.
Before you add more fish please plant it out with live plants. I recommend 30-50% of the tank volume in plant. The catfish and tetras will be much happier then.