I had a silver aro that I grew from 4" to about 28". After a year of having it, I could literally 'pet' it and it wouldn't get spooked. So I concur with others and say that it takes time. Also, the more you mess around with your aquarium (rearranging decorations, netting out fish, etc...) the longer it will take. Because each time you do it, you're reenforcing the fright & flight behavior in your aro...