Feeders often can carry diseases from the store that you purchased from. They also don't carry very much nutritional value for your RTC Personally, I stay away from feeder fish but if you are looking for something for your RTC to hunt down, I sometimes feed him red claw crabs that have been quarantined for a week. It is said that the crustaceans bring out their reds. To the second question , yes, store bought raw talipia is perfectly fine, nothing fancy.