Tetra fish are an excellent addition to the Discus Fish tank.. An addition of these peaceful ornate fish really helps the Discus Fish feel more at ease. Tetra fish come in a huge variety of colors and sizes to fit any sized tank. Tetras are schooling fish and should be kept in groups of at least 6... I keep a school of 150 cardinal tetras in one of my planted 220 gal tanks. This creates an amazing visual display of flowing color.
