Campden Tablet – Sodium Metabisulphite proportions

One Campden tablet in 20 gallons is enough, equivalent to 1/16 of a teaspoon in powder form of Sodium Metabisulphite. It doesn’t hurt to add too much though since it will dissipate into the air after 24hrs.

Also each Campden tablet weighs approx 500mg, but as there are other chemicals within the Camden Table, you could say that is probably only 400mg of Sodium Metabisulphite. As the chemical dissipates within 24hrs, it would be no problem to add 500mg of Sodium Metabisulphite in 20 gallons.