It really depend on indiviual thats wat i think, i have 5 ornates and all grow at a diff rate. It depends on their diet too to some extent.Maybe other keepers may have more specifics, have fun wth your ornates
Growth rates can vary from individuals,to optimize growth Keep the water clean and low80's.Feed a varied balanced diet including a good quality pellet.
if possible a few small meals are better than one big meal daily-Anne
I had one for about that time frame before I traded it in to make some room for some bigger fish. It probably grew 1/2" the whole time I had it. It was fed 2-3 times a day and 50% weekly water changes.