You can certainly use the Biorb for culturing copepods. It could be tricky to make it into a reforgium though... You have the light, but no holes or (more importantly) bulk-heads installed in the acrylic. To make it into a reforgium, you'd have to drill a hole in the biorb, towards the top. Getting a nice finish to a hole in a 15l Biorb though, considering it's made of acrylic, will be difficult. Getting a bulkhead to fit in there and make the hole and it's associated plumbing waterproof will the the trikyist part though. You'll somehow have to get a bulkhead to fit a curved surface, and I'm not sure if such divices exist.
All the best
Rabbut