Check the compatibility issues with your livestock.
I bought some really cool looking red algae and it was decimated by my fish and hermits. Probably really healthy diet, but not what I had in mind when I got it.
If you have a fuge you can keep it growing there and add to the DT.
Ust bought a piece of halemdia but it doesn't look like it has any roots should I glue it to a rock or just place it in the sand were does it usually grow on rocks or in sand