Question
I have a 6.5" diameter X 16" tall clear glass cylinder that I want to make an arrangement in for a wedding.  I will use white hydrangeas and I will place the stems in a smaller container, inside the larger container.  What could I use between the smaller and larger container that would enhance the arrangement?  I have thought about clear glass "rocks" at the bottom with fern leaves around the sides.  I don't want to use potpourri or all "rocks".  Any other suggestions?

Answer
Do you have a Floral Supply Syndicate in your area?  There is a product on the market that comes in various colors & shapes.  They are called aqua crystals - when submerged in water they expand to look like colored marbles or clear "crystals" - depending on the product choice that you purchase.  Look on www.fss.com and type in aqua crystals in the search.  

Another suggestion is to use colored water for a contrasting look - tint water with food color.

Will it have enough room between the vases for small orchids ( oncidium orchids or James Story orchids )to float?  

How tall is the smaller container?  Will it come up to the cylinder vase?  Do you have a picture of the container & vase?  By looking at it, I can give more suggestions.  :-)