My father and I were breeding and raising clownfish for a while. We had 3 29 gallon tanks for 3 pairs of breeders. bare bottom no substrate 29 gallon tanks with 1 flower pot.
The fish would spawn like clockwork about once a month, eggs hatched in about 8 or 9 days if I remember correctly.
The grow out stage, from 1 day to 3 weeks the fish were kept in a 30 something gallon hexagon tank, with all the side glass tapped up (the babies don't like light from all angles, only from the top).
After that point we moved the babies over to a series of 8 55 gallon tanks to grow out to 3 months. At that point the fish were between 1/4" and 1/2", not really a sellable size, and we were sitting on several thousand fish with no more space, so we stopped breeding and sold off everything as it got big enough.
It was fun, interesting, and on a small scale I think I may do it again at some point, but trying to do it as a source of income without a huge facility isn't worth the hassle.