I would say a 6 lb bass would have a length of 20 inches so I would say 5 or 6 inches but if you could get them to 8-10 inches, they would have a much better chance of survival. Being located in LA and feeding them, it would be possible to 8-10 inches a year. What brand of fish food are you feeding? I would switch Aquamax as it is the best on market.