vacuuming sand bed?

[maplereef]

I wanted to ask if most people vacuum the sand bed from debris? I have a few spots that are hard and crusted but not from coraline algae..if i break them up it creates a pretty dirty cloud
I have lots of bottom critters, sand star and 2 brittle stars but i still get these hard spot :(
advise and opinions are greatly appreciated
thanks :) :cheers:

[theo]

What is your subtrate? I think if it is crusting youll have to stir it up on occasion. I don't vacume the floor of my tank very much but I do stir it up when I do water changes. Just to keep it fresh looking.:)