Red Phantom Tetra (Hyphessobrycon sweglesi) The Red Phantom Tetra is one super hardy fish and does well in community aquariums. Vibrant red colors once established in a tank! Size is about half an inch to an inch or so. deep red with a diamond shaped body these little fish are excellent schooling fish! Often confused with the Serpae Tetra, the Red Phantom Tetra is more vibrant in color. Typically kept in schools of 8+ for natural behavior and for temperament, a single fish may become a fin nipper of other types of fish in a community tank but are well behaved in a group. Perfect for small to medium sized tanks as a tetra they are hardy and easy to care for.