Trigger For Conditional Formatting To Hide Rows

I found in this forum some vba code to insert into an excel spreadsheet a routine to hide rows if a value is < 1 in a column (Column B for this example). My problem is that it executes as you go down each cell in column B. I want to press a function key at the end of working on the spreadsheet to have it go line by line to hide rows that meet the condition. The code is as follows:

Private Sub Worksheet_Change(ByVal Target As Range)
Application. ScreenUpdating = False
' Dim R As Range
' Set R = Application.Intersect (Target, Range("B7:B7"))
' If R Is Nothing Then Exit Sub
With ActiveSheet
For Each Cell In Range("B5:B6")
If Cell.Value < 1 Then
Cell.EntireRow.Hidden = True
End If
Next
End With
Application.ScreenUpdating = True
End Sub