With Thermal Expansion installed:
Without Thermal Expansion installed:
The BioReactor has 18 total storage slots, although the "bar" of storage can only contain once a type of item. (ex: You can't have 2 stacks of seeds in the storage "bar".) All the extra items of the same type go in the top 3x3 storage slots. The BioReactor does not require any power, it only requires some sort of plant material. 1 plant (Seeds or Saplings) will create varying amounts of units in the buffer of the machine which can hold a total of 8000 units. Then it converts these units to BioFuel on a 1:1 ratio (unit:mB of BioFuel).
There is a 3rd bar in the GUI of the machine called "Efficiency" which determines the amount of units/plant. To get more efficiency, you must have different types of plants in the "bar" buffer. If you only add Seeds, that will give you 80 efficiency, 80 units/plant. On the other hand, if you had Pumpkin Seeds and Seeds, you would have 180 efficiency, giving you 180 for 1 Seeds and 1 Pumpkin Seeds thus you gain an extra 20 units at the cost of 2 types of items simultaneously, making varying farms more efficient at producing BioFuel than a single, large farm.