the more light the better, just keep an eye on the temps, but the more light will give you more growth and in the end a bigger yield, so i would say go with the more light, just keep an eye on the soil moisture as it may take more water with the extra lights but dont over water, and also keep an eye on the temps at the top of the plant, around 78 is what your aiming for, but either side of this is ok.
did you say what you was watering the plant with, are you using RO water or standard tap water, if your using standard tap water like i am then make sure you leave it to stand for at least 24 hours to remove any chlorine, i leave mine out for a couple of days and each time i water i fill the jugs back up and leave them sitting around till i water next, just make sure their not near a window to prevent the water turning green