6 legged bug

Question
I found a small long bug with 6 legs and a kind of split or fanned tail in the filter part of my tank.  Do you know what it could be?

Answer
Hi Hazel,
It sounds like it got in there somehow.  I dont think its an aquatic insect.  Most aquatic insects remain small and have appendages that allow it to swim underwater.  6 legs and easily visible probably means its a land insect.  Either way, it does not belong in the tank.
-Matt-