bio filter

Question
Two weeks ago we bought a used 10 gal aquar. for a black moor.  I didn't know the first thing about filters, but the girl said: "change the charcoal filter and just rinse the bio filter"
Soooo, I rinsed the bio filter in regular tap water and now after reading find that was wrong and I prob. killed the good stuff.  So, should I start from scratch and get another filter that will belong to "my" fish, or just let it go?  (She just took her fish out, drained the tank and sold it to me) Also, how often should I change the charcoal filter? Tonight the water was smelling a tad fishy so I changed the filter and really quick the smell was gone. It's just been two weeks.  It's an Aqua Tech.  Thank you in advance for your expertise.
marjie

Answer
I think it would be safe to just let it go, as when the fish tank water cycles through the bio-wheel. There is no chlorine in that water, which should neutralize any cholrine that might have gotten in the bio wheel. It shouldn't be a problem. The carbon in the filter should be changed every month.