very nice, i notice you have put this straight into your 300g.
I would advise removing it keeping it in a smaller tank and then you can feed it properly.
I currently have 11 bass growing on and i'm feeding them up to 6 times a day with bloodworm. I bought them at 3" about 1.5months ago there now edging towards 5".
if hes eatting right out of the bag thats good.... like mine they wiill be aggressive fish.... what type is he? straight in the 300g thats good will grow faster.... but i reccomend you dont only keep one peacock for there colors wont be as good and they will be more aggressive towards other fish.
Yes it could grow faster in the 300g but only if it's getting the food it needs at that size. If I put my bass in my main tank and tried feeding 4 times a day then the bass would end up with barely any food.
your guys are very nice but super plump i bet even if you dont feed them for 2 days lol i like the natural slender look.. as they get bigg they will get big shoulders either way but will have a longer looking body.... its all in the genes too i guess