I would vote that its inconsequential if you add more or not. Only a quality low range ammonia test kit can tell if you have enough, but going off open corals that do not like true .25-.5 levels you are prob ok. The right move is to change water by a larger percentage than you normally might do as an insurance that you moved over enough active surface area to handle the bioload in the new tank.
Your move of the sand has likely upwelled some nutrients that w fuel that algae, and the fish bioloading is decent for this size tank, so that w add to the algae challenges but it wouldnt be hard at all to contain. Currently, the algae is being fed and not grazed and thats how the algae has a foothold.