I double stuff 5" rounds and fill it (a little bigger than golf ball size) with water, and tie that to the bottom (stems) of the bouquet. Then very gently push the water balloon into the center until it fits comfortably into the center and the stems are snug in the hole. That way it gives it a little extra weight also to hole large bouquets upright. Just make sure the water balloon is not too big or it will sit lopsided. I never fill a geo with water anymore...I delivered a birthday sculpture once that had water in the geo...and I told the customer to make sure nothing sharp got next to it. They put it on the food table, where there was no silverware. They did have crusty Italian bread sitting close by though..and one of the kids accidentally pushed it up against the geo. The customer said it wasn't a pretty site...lol.

When Bread Rolls Attack

You have to watch that crusty bread.......Probably jealous of your pretty balloons getting all the attention

LOL...I wish I could have been there to see it. It was a 16" blossom half filled with water Who would have thought bread would do such damage...lol!