I have two large yellow cukes, a tiger tail cuke and a pink cuke. The tiger tail and pink cuke are nocturnal. But the other two are always out and cleaning. They are the best sand cleaners in my opinion as they do not disturb the sand bed. They clean the top of it.

They also do an excellent job of it. I also have two queen conchs that are excellent lower rock cleaners. They can get that snout in the smallest of places.

Also, the cuke I am calling a tiger tail is the one that attaches it's tail under a rock and only cleans around that rock. Then every so often it unattaches and moves over to another location.

Look at my tank in my sig and go to Tank Pics. Then go down the page and you will see a great shot of the cuke doing it's job, along with a queen conch working away.