When is it time to add a second super?

In early fall I added a second super and the bees took all the honey from the first super into the brood boxes. When we realized they had taken all the honey out of the first one we removed the second super. It is now summer and our brood box and super are full not lots of honey, but the colony is huge. Any advice? Could I split the hive or maybe try to add another super again?