A neat concept, for sure.
Only trying your design will tell you if it works, and what the problems might be. Unless you're a laminar flow engineer, and can model it on the computer.
I would worry that the large triangular area where the lure is suspended would tend to have it's own circular water rotation, instead of the water going around the top of the tank, down the far side, and under the triangular block.
One way to try and keep a vortex from forming in that area might be to extend the vertical side of that triangular block that's on the pump side up above the water line, and drill a hole for the pump pipe, to force the water for the pump to be drawn from below the triangular block, instead of some of it coming back over the top. That should promote a more circular flow pattern, especially if you keep your water source up near the surface.
And a narrower tank might make the flow more consistent, and help to avoid side vortices.
I don't know if this is possible with your sump pump, but rigging a valve in the outlet pipe, so you can control the amount of current flow, might be a good option, so you don't just wind up with a tsunami all the time.
Let us know how it works out.