I recently had a problem with a Magnifica and a Tunze power-head . The Tunze was alternating between high and low flows. The Mag was on a rock, and gradually moved toward the power-head. As it approached the power-head it managed to get blown apart - it never made contact with the power-head and wasn't actually chewed up by it. Anyone ever seen this before? Any possibility the Mag was already in trouble, health-wise, and intentionally self-destructed?