Clear bubbles

[jwill275]

I just changed my lighting on my 125 this past week, went from pc to T5 72"Nova Extreme Pro) I've noticed some clear bubbles on some of the rock, it blows off quite easily. Sorry no pics right now but does anyone have any idea what itmay be?
thanks

 

[candycane]

There are about multiple forms of alga that will capture bubbles under it, if that is what it is(?). What color is it?