If you don't recover the Methanol you'll need 2% Magnesol by weight. If you do recover the Methanol you need half the Magnesol or 1%.

I make 50 gallon batches, and use 3.75 pounds per batch.

I don't use an "appleseed" style of processor. Mine is "open" style, and uses a mechanical mixer. I use this same mixing tank to mix my Magnesol also, which cuts down on the equipment needed.