I had one before. They do get big and they grow pretty fast too. They are big eaters and are pretty aggresive. Beautiful fish if you have the room for it. From what I see of the size of your tanks, I wouldn't get it. I had mine in a 95 gal. and I got rid of it because it got too big. When it came time to feeding, it would get so excited and it would splash so much water out of the tank & on to my walls.