When and how to start with corals...
Corals are in a way a responsibility: their collection in the wild likely cannot continue unrestricted: there is already a call for certain ones not to be collected. Communities have taken to aquaculturing them---putting them in lagoons where they can be grown in native waters, rather like farming.

And we can grow them for domestic sale or trade. Certain ones are quite easy to grow and break apart for sale, and if you want to get into this,...