sand with crush coral?

[thai]

I notice there are people who mainly have a sand bed in there sw tank but also have a thin layer of crush coral on the top of the sand bed. What is the benificial of doing that.

 

[small triggers]

nothing really, its more personal preferance of the look. crushed coral does ad some calcium,,, but just a skim layer ontop wont really do anything. Why not just do coarser argonite if you like the look of larger grains? I have a mix of argonite and live sand in mine....

 

[kronos5]

I was schooled in the fact that crushed corol will hold leftover food and other debris which in turn will cause your nitrates to be abnormally high.