Reminds me of all the wild ones I catch whenever I go fishing. All are extremely aggressive feeders. Can't even count how many times I would toss a lil greenie back just to catch the same one again 5 mins later like they never even got hooked in the first place lol. As for a green sunfish in a 50g I'd say that's too small long term, they can reach a size of 12in in the wild and can weigh upto 1.5lbs. A lone one in an 80g maybe but not a 50g. This girl here apparently caught the state record greenie in North Carolina, no clue who she is but still a big greenie. Btw I just got this pic from Google.
