I am; I add about a 1000 mgs to each half gallon jug of water I drink, so 4000 total (2 gallons a day).
His advice of 10-12 grams a day is geared very highly towards people whose bodies have that sort of demand. If it's winter, and you don't sweat much, it's a lot different than doing double workouts in the heat of summer.
Highly individual, I would increase slowly if you think you need more, hold it there for a week for body to establish homeostasis and rid itself of excess fluid retention, and go from there.
I needed to increase it to match my water intake and based it off my performance in the gym. Best to autoregulate it yourself.