My floor is covered with rock but there are two 7"×3"×3" sandbeds I created for my two halichoeres. They don't use them. The yellow wrasse slept in a shallow patch of sand the first day I got it but I cleared the sand away while adjusting the rockwork. It started using a cave for sleeping and hiding. I replaced the sand but the yellow wrasse never went back to it. The red wrasse also retreats to the cave and probably sleeps there too. I've never seen them dive into the sandbeds I made. Will they start using the beds when they outgrow the cave? Or will they start stressing?