And I mean Scalare and not Altum species. I got a gold and zebra angelfish when they were babies about six months ago, so I think they have to be around 9 months old. I have seen bigger angelfish, but I read somewhere that once they reach close to the one year age, they still grow, but slowly. This specie is elegant, and is a cichlid! They require a tall tank because of their shape. While african and other south american cichlids need more horizontal space to swim because of its elongated shape, angelfish move more in a vertical manner. I believe a 40 gallon tank(3 ft long) will be ideal for them, or a bowfront close to 30 gallons too.