i got good growth out of mine till it hit 6". at about an inch a month till 5" then 1/2 inch after that. dont know what he is now though had to give him away.
i see you use doromin. mine wouldnt take it as i tried to switch due to him getting rather large for prima pellets.
i used a good pellet for the morning, tetra prima. the most important meal as it has all the essentials in it.
afternoon was algae wafers/gut loaded crickets. alternate days if i had both in or algae wafers if i ran out of crickets.
evening was either frozen bloodworm or frozen cichlid mix (bloodworm, mysis etc).
weekly water changes of 30-50% depending on the food used for the week.
good looking young one there mate. good luck.