I would think only for the tiniest babies. With my Korlias, the propeller is pretty small. I would think that it would be at least a 50/50 chance of them not even hitting the propeller. Not sure if the 400 GPH has a bigger propeller, but I would imagine it would. The outside of the pump is the same size, so it should be bigger.
Thanks for the info. I have a small powerhead in my shrimp tank, and I use various bits of filter or cloth over the intake with a rubber band to hold. I wanted to use a circulation pump, but like I posted, I thought the prop would be a death trap. It certainly looks more elegant than what I'm using now.