I have had some pretty good experience with LTP. I kept 2 for a little more than 2 yrs before I gave them to my dad, both of them are still alive in his tank going on 3 yrs now. I fed them finely chopped up raw shrimp meat which was dipped in selcon and garlic. I plated them on the sand bed with lower flow. But enought flow that all tectacles are waving around very gently. They do move across the tank, but not fast at all. You will be able to see it move it before it goes to any places that are dangerous. But once they are eating and the flow and light is good for them. They stay.
My tips to you is, do not move them once they are set, or if you have to move them, make sure they are all close up so you won't damage any tissue. Any tissue damage is real bad for these guys, they tend to not survive very good. Also try to find what kind of food they like, and make sure the food they take are finely chopped up and in tiny pieces. That way the food will not rot inside them and they won't die from the inside.