I have a 400 gallon (1500 L) pond with two oscars , two tinfoil barbs and a 10" silver arowana . I 've had this arowana for like 2 months and it hasn't try to jump out , yet. it has plenty of room to swim around ( around 3 sqm) and if it want to jump out , it is possible to do so since water is few inches below the edge .. Please tell me if I still need to cover the pond with a net in this situation . thanks