Yeah as soon as he reaches 15-20cm i will move him to a 700L tank with my rays until he can go down in my pool with the bigger fishes. As for now he is quite shy but at least he eats when the tank is dark. I switched the light today to a regular lightfixture from a 8000 kelvin led to keep the light dimmed down.Even in 720g, an 11" sperata will get their foods, either frozen or live. For a catfish, they are fast & agile, even during the day they will catch their prey. So anyway, hopefully you can achieve great growth rate, keep on updating.