If you are new to the hobby or you want to learn a little more about choosing the right substrate for your aquarium then take a look at this article from guest contributor, Robert Woods.
http://aquanerd.com/2018/09/how-to-pick-the-right-substrate-for-your-marine-aquarium.html
http://aquanerd.com/2018/09/how-to-pick-the-right-substrate-for-your-marine-aquarium.html