Sorry it was rather late when I posted this. I bought the tank about two months ago, it took me a day to set it up and it had been established a year before, as I bought it from someone. I waited two months for my water to level off and he was the first thing I put in it. My levels are fine, I've been going really slow. I brought two clowns back from vacation and added them last night and they're fine, but I still can't seem to find the cucumber.
I did add 20 lbs of sand right before I left, but I kept about an 1 1/2 inch of the previoius owners sand that from my experience, seemed to be loaded with goodies for the cucumber. I put half the rocks on one side and took half out, and then added the sand. I saw him attached to a rock as I placed him back in. That was the last time I saw him. Could he have burrowed himself to the old sand to eat it? I'll upload pictures asap. He's also a tiger tail.