You do have a hydrometer right? David is (as usual) correct in that you need a stable gravity before you call it 'done'.
the campden tabs (and usually potassium sorbate) are added to stabilize the wine in two ways:
1. sulfite binds with oxygen, so it helps stabilize against oxidation
2. sulfite and sorbate kill off yeast, to prevent renewed fermentation in the bottle, which could be dangerous (glass grenades)
Primary: English Mild
On tap: Pale Ale, Lancelot's Wheat, English Brown Ale, Steam Beer, HoovNuts IPA
Bottled: MOAM, Braggot, Raspberry Melomel, Merlot, Apfelwein, Pyment, Sweet mead, Cabernet
Gal in 2009: 27, Gal in 2010: 34, Gal in 2011: 13, Gal in 2012: 10