How to compare two datatables rows and make a new datatable? - asp.net

Question

I have two datatables. One datatable that has account and balance and the other datatable has the fee and the balance. For example:
Datatable 1
111111 35.00
111112 50.00
Datatable 2
111111sf 5.00
111112sf 8.00
New datatable should show the account from datatable 1 and the total balance(datatable 1 and datatable 2)
111111 40.00
111112 58.00
how can I compare the two datatables to go through each row and add these values and then create a new datatable? I did it with three gridviews and List(Of string) but it was dirty. I would appreciate any help.
Here is my code:
sqladapter = New SqlDataAdapter("SELECt account, balance FROM DEBT WHERE (account = #account)", conn)
sqladapter = New SqlDataAdapter("SELECt account, balance FROM DEBT WHERE (account = #account)", conn)
Dim ds As New DataSet()
sqladapter.SelectCommand.Parameters.AddWithValue("#account", 111111)
sqladapter2.SelectCommand.Parameters.AddWithValue("#account", 111111)
sqladapter.Fill(ds, "WithSFDT")
sqladapter2.Fill(ds, "WithoutSFDT")
'get datatable
Dim dtWith As DataTable = ds.Tables("WithSFDT")
Dim dtWithout As DataTable = ds.Tables("WithoutSFDT")
Here is the dirty code in gridview:
Dim itemlist As New List(Of String)
For Each row1 As GridViewRow In GridView1.Rows
If row1.RowType = DataControlRowType.DataRow Then
Dim gv1Value As String = row1.Cells(1).Text
Dim gv1col3 As Decimal = row1.Cells(2).Text
Dim lname As String = row1.Cells(3).Text
Dim fname As String = row1.Cells(4).Text
Dim TOdate As DateTime = row1.Cells(5).Text
Dim debtnum As Integer = row1.Cells(6).Text
For Each row2 As GridViewRow In GridView2.Rows
If row2.RowType = DataControlRowType.DataRow Then
Dim gv2Value As String = row2.Cells(3).Text
Dim gv2col3 As Decimal = row2.Cells(1).Text
If gv1Value.Contains(gv2Value) Then
GridView1.Visible = False
GridView2.Visible = False
GridView3.Visible = True
itemlist.Add(TOdate & " | " & gv1Value & " | " & fname & " " & lname & " " & " | " & gv1col3 + gv2col3 & " " & " | " & debtnum)
ElseIf gv2Value Is Nothing Then
GridView3.Visible = False
GridView1.Visible = True
'itemlist.Add(gv1col3 + gv2col3)
'list2.Add(gv1Value)
End If
End If
Next
End If
Next
If itemlist.Count > 0 Then
GridView3.DataSource = itemlist
GridView3.DataBind()
GridView3.HeaderRow.Cells(0).Text = "T/O Date" & " | " & " Account" & " | " & " Name" & " | " & "Balance" & " | " & "Debt #"
' GridView3.HeaderRow.Cells(1).Text = " Balance"
'GridView4.Columns.Add(
GridView3.Visible = True
End If
The problem with is is that the Gridview3 shows the itemlist in one row and it doesn't look like a table.