if i remember right about the dates. about a little more than 2.5 years ago, I saw this guy for sale at a lfs , and the lfs owner said its his fish that he grew up for 5+yrs and that was about 15". About a month later, it somehow ended up to a fellow member on this site ( milokai), and he sold it to me. And now, after countless bags of massivore and costco tilapia fillets, at a impressively proud 21" .
so, my guess would be 7-8yrs?
*note to all you baby dat growers out there , take good care of them and they can be with you for a long while : )