What is this?

[malazarock]

Hi All - noticed this white hard stuff forming in the grout lines in the coping around the pool. The picture attached is the worst one. Any suggestions for cleaning this up? I was tempted to start scraping with a putty knife or something, but didn’t want to do any damage.
Thanks for all you do!

 

[Richard320]

Use the search box up above on Efflorescence. There are several older threads discussing it.

 

[malazarock]

Thanks that’s helpful!