Crabs part of your CUC?

[Simmy]

I added about 20 snails last week from JL boxing day and my glass is looking nice after 1 week! I used to always have algae/detrius build up in the bottom of my tank just above the sand where I can't use the magfloat to scrub for fear of catching sand between the mag and scratching my glass. I looked last night and the build-up that used to be above the sand is gone! I added Nassarius and Cerith snails.