I started my marine tank in Jan 2013. My reef tank is 4 x 2 x 2.5. Recently one new fish has died and found lodged under a pile of rockscape. As it was lodged under a large piece of base rock and was not visible from the top of the tank, I need to use a long object to "dig" blindly for it. I spent a good 15 minutes trying to retrieve the body and the base sand (very fine type) has been disturbed at the localize area due to the digging. After this, my most hardy fishes and fishes that has been w