The more of these, and other similarly sized labeos the better. My wife had 2 RTBS and a rainbow and a white fin shark. Since she upgraded tank size she now has 6 RTBS,1 Large 1 medium 4 small, 5 White fin sharks, 1 Large 4 small, and 1 Large Rainbow. Their aggressiveness is almost nonexistant. They do chase each other to an extent, but even that has become almost nil. They actually will school once they get to large numbers. Much better this way. The one RTBS that is medium sized has grown up with the other 3 large sharks, but got the shaft and alwasys picked on. Now that there are smaller ones he is healed up quite well, and is growing very rapidly.