My opinion:

DO NOT ADD ANYTHING!!!


Hint: Everyone's telling you not to.
It's going to cycle on it's own. Anything you add is only going to extend or increase the cycle. The object is for the cycle to end. Since you've added more shrimp, expect another cycle to come again.

And after you think the cycle is finished, expect to see various algae blooms. It has to go through it's own process, and if you try to speed it up, your going to cause problems later on.