Since with saltwater, substrate matters highly when it comes to keeping those living inside the tank happy - what substrate do you tend to use?
I tend to stick with fine grained mediums that are around 0.5-1.7mm in grain size (mixed with some super crushed calcium) in order to allow for some sand shifting fish like my gobies to be able to dig (and be happy), while also having the benefit for the nitrate reduction done inside of the tank naturally.