Tent size and lamp strength are just two of many factors that influence this. It can contain anything from 20-100g. But what I can say with certainty is that 100w is simply not enough for the growing area. 300w or more would be recommended there. MH and Spidey have very good lamps at a reasonable price. This would also allow upwards of 100g per plant, with 3-4 plants in the tent you still have some space to work with and still get a decent yield.