I agree with using a fishless cycle. Although a lot of people on this board have enjoyed success with bio-spira, I ended up getting a bad batch from my LFS. You don't want to risk having to cycle your tank with a full load of fish. Think of 4-6 weeks of daily (or even twice daily) 30-40% water changes...not good.
You could also try a combination of the two; fishless cycling while using bio-spira might be quick if the bio-spira works. While you have to make sure that there's already ammonia in the tank for the bacteria to feed on, you don't want to have too much. I don't know the specifics of how much ammonia to put in while using bio-spira, but someone else should come along shortly that knows.
Btw, you would put the bio-spira directly into the water, not your filter.