Do you know about the nitrogen cycle in a new tank? Read the link in spoonmans signature titled "cycling with fish" and/or do some research on this site on the subject. Running a tank for a week is just circulating the water...it is NOT cycling. This is a very common misunderstanding.
Read that article, get a master test kit and some Prime water conditioner, and get ready for some water changes...lots and lots of water changes! Many people here can help you get thru a cycle with fish, but you need accurate test results so that you (and we) know what is happening in there.