1 teaspoon recommended per gallom. But then camden tablet would have doubled up
You haven't doubled up as you said earlier -
Stabiliser contains sodium metabisulphite and potassium sorbate. Cambden tablets contains sodium metabisulphate and polethylene glycol. Because looks like both contain sodium metabisulphite do you think it will still be drinkable?
They are both a mix of two chemicals so you are not putting 2 teaspoons of sodium metabisulphite into each DJ.