Is this a calcium deposit?

[Billrector]

I have a white, hard growth in a particular are of the pool. Can you tell me what caused this; how I can get rid of it; and what to do to prevent it.

 

[Richard320]

That is called efflorescence. Moisture behind is coming through and carrying Calcium with it. Use the search box for efflorescence and you'll find some posts by people who know more than me.