CC is too coarse for the critters that live in sand. They will find it very hard to move in the CC and most likely will not even go into the CC, making it more detrimental than beneficial. Looks are another reason. The sand is much pleasing to the eye, reflects more light, and is way more natural. Make the switch. One suggestion, the crap under the plates, don't let it fly around in the tank(can be toxic). Remove the plates slowly and siphon the crap. HTH--Bob