What are the sand dollars in Quinn’s aquarium used for?

How are sand dollars used in this game?  Game help section is not helpful with this.

Pretty sad that it has been two years and no one can answer this question.

Hey at Flaboyjack Sand dollars are used to purchase items like fish, or as an option you can use them to speed up someones arrival.

As this thread has been inactive for over 2 years I'm going to go ahead and close it off to prevent further necroposting.