Three of my columns are set as centered. For whatever reason, some rows (out of 18000) will be right-aligned and it seems to be random.

I did this code.

    Worksheets("WhReview").Range("D6:F" & Range("F" & Rows.Count).End(xlUp).Row).Select
    With Selection
            .HorizontalAlignment = xlCenter
    End With
.... but it is painfully slow and takes minutes.

What should I look for to improve this?