Do Until replay tree times - excel

Question

I'm using this code to check if the cell is a number or not to delete it, but there are 3 columns that I have to do this. But Do Until only goes through it once and stops doing it, leaving the loop.. it changes the col to 5 or 8 as it is in the for
Could someone help me with what I'm doing wrong in this code?
Another problem I have encountered is that if the cell is empty, vba fills in 0 as a value, is there a way to leave the cell blank instead of putting 0?
Sub copy()
Dim Row As Long
Dim Col As Long
Row = 1
For Col = 2 To 8 Step 3
Do Until Cells(Row, 1).Value = ""
If IsNumeric(Cells(Row, Col)) = False Then
Cells(Row, Col).Clear
Else
Cells(Row, Col).Select
If Cells(Row, Col).Value = 0 Then
Cells(Row, Col).Value = (Cells(Row, Col).Value) * 1
Cells(Row, Col).NumberFormat = "$ #,##0.00"
Else
Cells(Row, Col).Value = CDec((Cells(Row, Col).Value))
Cells(Row, Col).NumberFormat = "$ #,##0.00"
End If
End If
Row = Row + 1
Loop
Next
End Sub

Answer 1

You can loop through the columns, but use special cells to determine if it is text or a number.
Based on your comment, it is either text or numbers, not sure why you would need to times by 1, or make value=value.
Sub UsingSpecialCells()
Dim ws As Worksheet
Dim rng As Range, LstRw As Long
Set ws = ActiveSheet
With ws
For Col = 2 To 8 Step 3
LstRw = .Cells(.Rows.Count, Col).End(xlUp).Row
Set rng = .Range(.Cells(2, Col), .Cells(LstRw, Col))
On Error Resume Next
rng.SpecialCells(xlCellTypeConstants, 2).ClearContents
On Error GoTo 0
On Error Resume Next
rng.SpecialCells(xlCellTypeConstants, 21).NumberFormat = "$#,##0.00"
On Error GoTo 0
Next
End With
End Sub

Answer 2

Clean Data: Apply Consistent Formatting in Columns
Option Explicit
Sub UpdateCurrency()
' Define constants.
Const FIRST_ROW As Long = 2 ' adjust: you have headers, right?
' Reference the worksheet.
Dim ws As Worksheet: Set ws = ActiveSheet ' improve!
' Hard to believe that you know the column numbers but not the worksheet name.
' Calculate the last row, the row of the bottom-most non-empty cell
' in the worksheet.
Dim lCell As Range
Set lCell = ws.UsedRange.Find("*", , xlFormulas, , xlByRows, xlPrevious)
If lCell Is Nothing Then Exit Sub ' no data
Dim LastRow As Long: LastRow = lCell.Row
Dim crg As Range, cell As Range, cValue, Col As Long
For Col = 2 To 8 Step 3 ' to not introduce further complications
' Reference the single-column range from the first to the last row.
Set crg = ws.Range(ws.Cells(FIRST_ROW, Col), ws.Cells(LastRow, Col))
' Clear the undesired values (all except empty and numeric values).
For Each cell In crg.Cells
' Write the cell value to a variant variable.
cValue = cell.Value
' Check if the value is not numeric.
If Not IsNumeric(cValue) Then cell.ClearContents
Next cell
' Apply the formatting to the whole column range so it takes effect
' if you decide to add numbers to the empty cells.
crg.NumberFormat = "$ #,##0.00" ' "\$ #,##0.00" if $ is not native
' Copy the values to memory, and copy them back to the range
' for the formatting to affect the remaining numerics
' (numbers and numbers formatted as text).
crg.Value = crg.Value
Next Col
MsgBox "Currency updated.", vbInformation
End Sub

Answer 3

Once iteration through the column 2 last row value is complete, blank row gets iterated and as per the condition Cells(Row, 1).Value = "" gets true and terminates the do until loop.
I have made small changes to your code and created the perfect working solution.
Sub copy()
Dim Row As Long
Dim Col As Long
Row = 1
Dim row_i As Integer
row_i = Cells(1, 2).End(xlDown).Row
For Col = 2 To 8 Step 3
Row = 1
Do Until Row > row_i
If IsNumeric(Cells(Row, Col).Value) = False Then
Cells(Row, Col).Clear
Else
Cells(Row, Col).Select
If Cells(Row, Col).Value = 0 Then
Cells(Row, Col).Value = (Cells(Row, Col).Value) * 1
Cells(Row, Col).NumberFormat = "$ #,##0.00"
Else
Cells(Row, Col).Value = CDec((Cells(Row, Col).Value))
Cells(Row, Col).NumberFormat = "$ #,##0.00"
End If
End If
Row = Row + 1
Loop
Next
End Sub