Sorry mate but my advice would be not to bother... if you really fancy doing a scientific experiment, use a different variable. Different nutes, different light, different wall covering (paint, mylar, foil) anything which is likely to have a positive effect, I'll bet my grow and my house that nothing beneficial will happen to your plants if kept in the dark for 2 weeks. The whole 2 weeks/1 week/ 48 hours darkness before harvesting was debated in detail on overgrow - I did not see one side-by-side experiment that made the blind bit of difference. The main positive contributers were just "wow look how crystally my plant is, i left it in dark for the week before that must be it!!!111"