++1 (is there such a thing with the extra plus?)
I ran the new filter in an established tank for about nine days plus transferred half the media from an existing filter and it was converting 4 ppm ammonia to zero ammonia/nitrites in about 6 days in the new tank.
Point being, you have access to established media so you are ahead the game. If you cannot find pure ammonia, you might try the stinky route with one fresh, raw shrimp. Or fish food. Either way, place it in a nylon bag so that it will be easier to remove.