The GS will not grow after the water temp has dropped below 50 to 55 deg. I sounds like you had a great survival rate on the fry though, and that is how it should be. These fish have also probably maxed out their growing space. When you add preditor fish in the spring you will see the numbers start to decrease, and feeding is an option that will probably only sustain them now if they are out of growing room so that is a personal call on feeding.
