Adding sand and keeping Substrate

currently i have a 50 gal salt tank with live rock. i recently added my first coral (polyps) and am looking into adding some live sand. right now i have a small base of crushed coral as a substrate. I planned to move the substrate to on half of the tank and exposing the bare bottom glass on other half. Then add some sand to that meeting up halfway in tank to the crushed coral. will this be ok to do? did i make sence with what my plan is. I hear that the sand will be better in helping eliminate nitrates and thought this would be a good idea. Please help/

 

It would be OK. A long time ago i took all my rock and fish out of my tank. Took out the crushed coral and added a deep sand bed. Your way would be fine. I wouldn't add all the sand at once though. I'd put maybe a cup of sand per day. Why don't you just add sand over the existing cruched coral?

 

The fine grained sand will slip between the coral and work its way underneath.eventually it will be on top
(c coral)

 

How about taking out as much crushed coral as possible then adding sand?

 

i had cc mixed with sand in a smaller tank i used a large size net and sifted the cc out of the sand. the sand was small enough to fit through the holes in the net while it held the cc. then i just added more sand on top