I would use re built mass 2 scoops at a time, morning, pwo, and before bed. That way if you mix it with milk you get over 600 cal. per shake, and over 50g of protein, plus you will save money. With mass gainers i see many people taking them 1 or 2 times a day, but if you really want to get a lot of size i would go 3.I wouldnt recommend tbomb at your age because your testosterone is already very high.