Disappearing Neons.....Whose the Culprit?

So with our Parrot Cichlid gone, I still can't, for the life of me, figure out where our neons are going. We HAD 9 neon tetras. And are now down to 6. We had 4 zebras, down to 3. Still have 4 GLOfish Tetras (pretty sure they are black skirt tetras).

The other fish:
Pool Comet
Rainbow Shark
Chinese Algae Eater

Is the CAE the culprit? He's starting to get pretty darn big, and my Rainbow Shark gets chased by him quite a bit. Which is just bizarre to me. They were in the same tank at the LFS, and have been in the same tank for the last 2 years. I don't think the comet is doing anything, so I'm pretty much between the Rainbow Shark and the CAE. The Rainbow Shark pretty much ignores everyone MINUS the Comet, though he's pretty territorial of his cave. Our tank is completely sealed except where the filter puts water back in. I checked the floor, and no fish.

So whose the culprit?

Comets eat Tetras? Never would've guessed lol. He's going out once the koi pond thaws, but he still has a few months.

He's getting pretty big. About 3-4" or so. These are pretty tiny Tetras. Would've never picked him as the culprit. Was mostly figuring it was the Chinese Algae Eater, as I've been reading they can get aggressive as they get older, and he's almost 6" long. And filter has nothing but water in it.