Hi Sabrina;
I am glad that you are excited about your tank but trust me you need to slowdown your enthusiasm ,in my opinion you don't need to bring yet another factor ( seachem purigen ) in to the equation , your test shows that you are in the middle of your cycling ,you filter is already converting SOME ammonia to nitrite but still have some time to go ,do your self a favor and read one of the stickies on fishless cycling . As Steve said all you need is little bit of ammonia to keep your good bacteria happy .
Good luck.