Sand movement

[AquaAddict]

I have two black knobby sea cucumbers in the gravel of my 100 gal tank. I never see them but the sand always looks 'healthy'. One time my Maxi Jet power head fell onto the sand and churned up the whole right side of my tank right down to the glass bottom. All I had to do was put the sand back, remove the one dead sea cumber and start up the power head again (reattached to the glass). All was well. I replaced the dead sea cucumber with another live one. All is still doing well.

AquaAddict