stinky tank

Question
hi. I received a tank from a friend. 10 gal. had held one goldfish. Stank to high heaven. I completely emptied it, wiped it down with paper towels with a dilute bleach solution, then rinse the heck out of it. Even after scraping gook off the lip, it still stinks. Looks great and clean, but stinks. Help? (of course, I'd like to get this up and running asap, but then, doesn't everyone?)

Answer
I really do not know what could be causing the smell.  Are you using the same filter?  There could be a buildup of detrius in there...but it is important not to change the filters or the water will be unsafe for the fish. i really am not sure what to do.