White Residue on Rocks?

[Addicted2Acro]

I came back into the office this morning and saw there is some kind of white buildup on some of my rocks that formed over the weekend. Have never seen this before. Any idea what it could be?

 

[Rocks reef]

Are you carbon dosing at all? Are you dosing anything?

 

[Addicted2Acro]

Dosing All for reef

 

[Gumbies R Us]

Do you have photos of your tank? video isn't loading on my end

 

[Addicted2Acro]

Do you have photos of your tank? video isn't loading on my end