A lot of aquarium keepers lose fish to run-ins with propeller based water pumps. The immediate reaction for the hobbyist is to blame the pump for the fish’s injury or death, but in all likelihood the fish or even the hobbyist is to blame. Fish are curious and will hover dangerously close to pump intakes, but if the fish were healthy, it would easily be able to overcome the suction force of the pump and swim away. After all, today’s propeller pumps draw in water over a fairly large area. What typically happens is a fish that is already weak and possibly near death wanders too close to the pump and gets sucked in. The fish can’t escape, eventually drowning or suffering from significant physical trauma. It is possible that a perfectly healthy fish can get sucked into a water pump, but the chances are slim that this will occur.