He's 3 in and after looking in to the temp it's 77 in tank and I live in Texas and it's 70 he's in a growth tank so a 30 gallon till he gets bigger then I'll move to a 55 then I'll move him in with my rtc in a 750 gallon he's vary lively but he doesn't go to the top of the tank to eat
3" is a good size already, so you can afford to wait a day or 2 for him to settle.
If the fish had been feed sinking pellets exclusively, it might not know to go to the surface for food. You can try sinking food or soak the food till it sinks to see if he will do better. <Also, if you have a bare bottom tank, it would be easy to see if he had eaten any of the sunken food.> I would not worry too much as long as the fish is lively & looking for food.
Koi & goldfish are quite intelligent. They will associate a certain spot of the tank/pond, the presence of certain people, or maybe even time of day with feeding time. So when they move to a new tank, it might take them a while to figure out where the food is & so on. This is esp. true if the fish is alone. When I have fish in QT, it is not unusual to see them ignoring food in the beginning, as the fish doesn't know that it is feeding time. The fish just spend all day looking for food & eventually will discover where the food is. <I leave the food in the tank for 24 hr or more ... not too much so it doesn't foul the water ... never have to fish out any that is uneaten yet ...>
When I move to fish to the main tank, the presence of other "trained" fish makes feeding much easier. They must be able to communicate somehow. As soon as the older fish go to the feeding spot at feeding time, the new fish invariably follows & learn about the feeding routine immediately ....
