This is a Gigas grow out thread, so here are pictures of my two Gigas. I got the first one in my tank on 7/10/2019 and the second one on 7/17/2019. The first on did very well and start to grow right away. There is no significant border on the shell between before and after arrival into my tank, other than change in coloration. Of course, to obtain this growth rate, we must supply them with adequate Ca/Alk
It is different with the second one. He arrived really cold and took several days to recover. Even now, he does not open as much as the first one, but he also have start to grow again. Definitely, there is a ledge that separate the grow from before and after arrive into my tank.
Here are the picture. First Gigas growth from 7/10/2019, about 1/4 inch plus. The larger sea star is about 1/3 inches, the common sea stars that are in everybody's tank. Minimal ledge at the border that separate the growth
Here is the second Gigas, growth since 7/17/2019, ONLY about 1.5-2 mm, with clear step off between the line that mark the time I put him into my tank.
Gigas #2 not open quite as well and Gigas #1