white stuff on my rocks?

[scuba10110]

I just noticed that I have alot of white stuff looks like sand on my rocks. I dont have any live rocks they are just plain rocks.I dont know what this is. I have been fighting ich in my tank with Kent Rxp but dont know if this ich or something else? So know I question if I actually have ich or if its this?It is also on the shell of my hermit crab?

 

[smshep01]

How long has the tank been going? Do you have substrate and what kind is it? They could possibly be copapods or calcium deposits. Could be something else as well, but that's a start. Im sure others may have suggestions of what they are.
Hope that helps some.
Sheppie

 

[scuba10110]

Ive had the tank for 41/2 months. How do I get rid of the stuff?