mine went from 1.5" to almost 21" in the first year. Now it's been a year and 2 months and he's nearing the 24" mark. That's with several stressfull tank moves, a bout of fin and tail rot he had when I purchased him, a heater crash where I lost my big jau, and also the jau kicking the crap out of him and tearing all his fins all to hell. So in perfect conditions probably looking like it can do better than mine did lol.