new tank pics.

[pocilipora]

If you dig up your sand after years of being under a rock it will be black/grey and stink like sulphur. That is a dead spot and can causes algae problems. Its just an opinion and an experience. Have you seen most tanks. thats cool. Every point touching the sand is a place for detritus to collect and affect its long term sucess. In essence you create a brick wall which no circulation can go through.