They dnt need a big pieces of drift wood just a tiny one will do as long there is wood in the tank. Royal need wood to survive and the wood help wear down their teeths.
I long believed this to be fact. But another member on here has basicly proven to me that the dw isn't directly needed for their diet. Basicly it is a myth that they need wood in their diet to survive. That being said I would still never do it. I have seen how fat and happy mine have been with tons of wood in their tanks and I would have it no other way. I also feed as little protein as possible to my panaques.