Plant Attachments

  Does anyone now if there is some trace element that must be present for
plants like Java moss, Java fern and Bolbitis to attach themselves to
driftwood?  I have had several small aquariums were the plants were tied to a
variety of surfaces from petrified wood to coconut shells and they grew to
the surface just as planned yet for some reason they refuse to do it in my
big show tank.  I keep retying tufts of Java moss to my driftwood with black
cotton thread, yet as soon as the thread rots the moss floats away.  I can't
help but think that this tank is somehow lacking a key ingredient.

     Thanks for any recomendations, Nathan in cold and rainy Nashville