just feed them loads of cafeteria, cat and dog food. and they will grow to 3 ft in 2 months...and make sure they don't jump out of the tank just before you want to post their picture.
Nice! My African lungfish is over 30+ years and it is around 4ft (give or take). the only thing is the color on him is grey with black blotches and not the cool color of yours. He is a member of the family and I treat him more like a dog than a fish. these fish are not picky at all and have strong "personalitys". Too bad you can't keep them with other fish, but I wouldn't trade mine for ANYTHING!