White stuff growing on concrete
 

I have white stuff growing on concrete, we are replacing wood floors and the floor was bare 1 full day and night. The next day there was app. 1/4 in of that stuff in different areas of the floor, we haven't been in the house but 1 month and we purchased the house..how can i get rid of it, i'm on a tight budget PLEASE help!!!

Is it fluffy or powdery? Chances are it's efflorescence.

Jaz