Thanks for the compliments everyone.
EastAmherst, I will be trying to breed them (along with all my other pairs). I've never raised any percula, but I've heard they're a little slower to develop. We'll see what happens in a week or so.
ReefBoarder, I plan on waiting a little bit to move the tile. It may disrupt their cycle if I move it in after these eggs hatch. I would like them to get into a little rhythm before disrupting them at all.
From what I've read, it's not uncommon for a male cardinal to eat the eggs the first few times. He needs to get a little experience. I did a little poking around and he should release them after 7 or 8 days (not 3 weeks like I originally thought). So, he may have released them and they never made their way to the urchin by getting sucked into pumps, other fish eating them, etc.