Please tell me what this is

New tank owner

Reefing newb
Hello I was just given a salt water tank and setup over the past 2 weeks this while stuff has formed over one of the live rocks I don’t know if it’s good bad I don’t know much about a salt water tank at all please help me identify this and what should be done about it.


Thank you!
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If you are referring to the white blob on your rock, I believe that it is a sponge. They are common hitch hikers and don't require much attention.