Agree, it looks like a void ! Where is the usual algae, diatoms etc. fish only should provide nutrients for these.The tank looks sterile for one year old tank, not even algae in the corners, the heater, where the sand meets the glass, nothing. It looks like it was cycled yesterday.
Are the lights on? What type of lights, what intensity? Coraline needs good light to grow. Needs flow & nutrients, it needs good reef conditions to grow.