75 gallons, because the depth of it is 18", which is longer then the Oscar. Some people will recommend 55 gallons, but with a depth of only 12" this is shorter then an adult Oscar, and obviously not appropriate.
75 gallons, because the depth of it is 18", which is longer then the Oscar. Some people will recommend 55 gallons, but with a depth of only 12" this is shorter then an adult Oscar, and obviously not appropriate.