Heres what the inside of the cover looks like:
I circled the part I cut off. Now instead of most of the water being sucked in from the back, it gets sucked in through the back, and the top. I figure if you cut the tube on fo front off you can get the flow to be more widespread, and probably perfect for smaller tanks where you dont want crazy crazy flow.
Heres a video of the startup, and showing the flow The tallest rock on the left side was being rocked back and forth onto the glass until it fell into a place it liked.
