As mentioned in the Feeding Hatchlings section: In my opinion the most common mistake people make is feeding their hatchlings or juveniles live food, fresh seafood or krill as treats. These foods are very appealing to diamondback terrapins and unfortunately they can quickly decide that they no longer want commercial food. It is very common for them to refuse to eat anything other these treat items. Once this happens it can be very hard, if not impossible, to get them back eating commercial foods.
In most cases adults that were raised on pellets can be offered seafood once a week with a lot less of a risk of them refusing commercial food afterwards.
Here are a few tips that might help get your diamondback terrapin back eating commercial food again. First you should put the turtle in a tank with other turtles that are eating commercial food. I have found sometimes watching other turtles eat commercial food might help them get interested in eating it. Also not offering them any other food for five days will often force them back to eating commercial food. They can very easily good without food for well over five days.
Here are some commercial food that I have had some success with getting them back onto commercial food. TetraCichlid Jumbo Sticks are really big food-sticks and they have a strong fish smell. I have had success with using these food-sticks to get even wild caught diamondback terrapins eating commercial food. Another option is Omega One food-sticks. They are a lot smaller than the TetraCichlid Jumbo Sticks but have a higher content of fish in the ingredients. Over all the Omega One food-sticks are my favorite commercial turtle food.