So I'm convinced you can't keep a oscar for life in a 60gal. My friend on the other hand, thinks different. Apparently its fine to keep TWO oscars in a tank 1.2 metres long, 20 inches wide ( just over 45 cm wide ). With only sand substrate, no deco, and a 1500 litre rated powerhead with filter. Double 100 litres rated sponge filter, and a sump ( 20 litre bucket ) going to another sump full of hornwort. 50 percent water change weekly. What are your opinions.