I also have an orange tree sponge and am unsure how to make it grow or even just keep it alive. The funny (and not so funny) thing is I have black, yellow, and orange sponge in my tank. All of them are tanking off, all except the orange tree sponge. I hope some people can chime in because mine is slowly dying.
Sorry to cut in on your thread
![Big Grin :D :D](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)