Jamie,

DO NOT USE THE MODIFIED MJ'S ON A WAVEMAKER. After a few months of stop/start, the pumps will begin to startup in reverse. If the pumps are off, and an algea grazer is nibbling on the pump when it starts back up, they can be sucked into the impeller. I lost a blue tang and almost lost a yellow blenny.

I'm assuming the regular Koralias on a wave maker will do the same over time. Not sure why this happens. Maybe the magnet's polarity gets reversed or because AC current fluctuates in direction, but either way it will happen.