In the meantime, put something over the air inlet that will prevent a whirlpool breaking the suction early and turtles from plugging it. Maybe an end cap with a bunch of holes drilled in it, or stiff metal rods pipe clamped to the end to point up past the opening.
If something winds up preventing the suction break, you may be able to later walk down to the inlet at the bottom and see what is going on. Not that you would want to.
