I have 2 oscars, one is about 8 inches and the other is around 6. They are in a well planted 120 gallon. So far I haven't had any issues with them rearranging the tank? Every now and then a plant will be pulled up, but it's very rare. The sand is hardly ever disturbed. Is that normal? Lol I've heard they can be destructive. Is that something that will come with age? My tiger Oscar has developed a chin bump but I don't see him digging. I would appreciate any insight or experience! Just curious.