My first Arm I had about 8 years ago and never wanted to eat anything but live, he got to about 18" and then jump the tank

My problem was that I was too concern for him when I tried to starve him for a week at a time, I felt bad. It was in a tank full of other fish that were eating frozen tilapia so I was hoping they would teach it, but never happened. It was also about 10" when I started to try and train it. This go around I started early, around 5", bought two of them at around 3". I read something in a past forum that its easier to start when they are smaller. I figured 5" would be a good size. Not too small and fragile but not too old at the same time. At this size too they would have more body fat to loose. It took a good four weeks to train them to where they really started to like the frozen food. They were eating large goldfish prior to the training. To start I froze about 20 large goldfish and would only throw 2 in a day, every other day, thawed out of course. It only took about a week and a half to get them to eat the frozen goldfish. They would grab them here and there at the beginning and spit them out. When the 20 goldfish were gone I then used silver sides. This again took about 2 weeks for them to accept the new food. Same thing 2 a day every other day till they started to like it. Did that for about two months then switch to tilapia. Repeated the same process again, two small thawed chunks every other day till they accepted it. I also tried market shrimp with the same success as the tilapia. Just seems they like the tilapia better and silver sides the best. I had them eating tilapia up till recently when I went back to silver sides when I ran out of tilapia. Big mistake here, now they won't eat tilapia or market shrimp. Have to try and start the process again. Let me know if you have any questions. Been through this process a few times over my years keeping fish. They are all different.