This is actually one of my favorite topics to share about. Its not necessarily hard to get them eating frozen foods, its more so daring yourself to let food get all over in the tank. Im not saying to dump excessive ammounts of food in there. But leave a circulation pump on to get food towards the bottom. Dragonets are slow, their eye sight is different from every other fish. If you watch them closely, they dont have a long line of sight. Just what is close to them. I have a red and green mandarin in my 65, and they both chow down on frozen foods, whether its brine or mysis. The main thing is just letting get near them to catch on. I recently just put a spotted mandarin in my 20 gallon, and the second day of having him he already goes for the frozen foods. Theres no need to put them in a breeders net or anything to try and train them. They just wont come to the top for food like everyone else. And moving them will just stress them out. Ill try and make a video for youtube on it here soon. But i have not had any issues getting mine to take to frozen foods. Nor have i had to actually "train" them to eat it. When i feed my tanks, i turn all pumps off except for one circulation pump, and thats just to make sure the food gets to the bottom. Now, i know a lot of people will argue this, but, if you have an adequate clean up crew, enough coral, and know your other fish will run around grabbing every scrap they can, its not at all a bad thing to let the food be sent around the entire tank.