Thank you for the answer! What do I do about all the duplicates already out there. It looks like, before my arrival, there was a JE done to reverse duplicates. 

Would it not be better to simply delete all the duplicates? Can I simply go in and delete all the duplicates that have occured this year? 

If yes, do I need to go to the ledger and do one by one or is there a quicker way?

Thanks!