did you look up silver gar or a different fish...the video you posted was of a characin...your fish would have a simmilar body structure to the silver gar, but the colors would be diff...i'll try to find a pic of the fish i am referencing...
i have my 17"+ gar with my 10-12" silver aro...i added the aro at 8" and the gar was the same size...had one reaction bite from the gar and thats it...
ok still trying on the picture. sorry got a lot going on right now. cookin dinner, taking new readings of the tank and setting up a photobucket account.. now heres where the readings r right now on the tank. nitrate is at 10ppm and nitrites r at 1.0 ppm