I have a Regent filter on my 10 gallon, so I know exactly what kind of filter you are talking about. You got it at Wal-Mart, right? The 29 gallon combo?
My beef with these filters is that there really isn't any good place for bacterial growth inside the filter. It took me almost 6 weeks to get my tank to cycle, and in the end I finished it off by floating a biowheel from my Penguin 330 filter on my other tank.
As far as changing the filter pad, you don't need to change it as often as it says on the box. I know that it is shocking that the company that sells and profits from the sale of a filter pad would tell you to change it more often than necessary, but that's how it is. hehe!
When I do water changes, I take the pad out, and rinse it off in the water I just siphoned from the tank. Never rinse it in tap water, as the chlorine will hurt any bacteria that are growing in there. I only change the pad when after I have rinsed it, I put it in, and it is still overflowing. When no matter how well you rinse the pad, the water is still overflowing back down the chute where the intake pipe is coming up, it's time for a new pad. I hope that made sense...
Also, after your tank becomes established, changing the filter pad won't throw all your bacteria away. Bacteria will begin to grow in your gravel and on your decorations, in fact with your filter, I'm guessing that is where the vast majority of the bacterial growth will be. And if you were ever so inclined, a Penguin 170 or 330 would be a fine choice for that aquarium, and would have a biowheel to store good bacteria on. You could try Voodoo's idea of putting media in the filter, although I don't know if that will work. I couldn't get anything to stay in the space where there is room in my filter, and there certainly isn't any room behind the filter pad for media.
I hope that helps. By the way, if your tank is still going through the cycling process, it seems to me that you started with quite a few fish! I would keep a close eye on your water parameters (ammonia, nitrite) to make sure that the levels stay non-toxic, and be prepared to do water changes if those levels do come up.