It is not going to fill the oceans with cement, it is a naturally occurring algae. I would like more information about how you get limestone and not just powder

It is not going to fill the oceans with cement, it is a naturally occurring algae. I would like more information about how you get limestone and not just powdery calcium carbonate. A slightly better link at: https://www.colorado.edu/today/2022/06/23/cities-future-may-be-built-algae-grown-limestone https://www.colorado.edu/today/2022/06/23/cities-future-may-...