Originally Posted by Unknownfigure
I remember seeing one of your previous threads, and if I'm correct, you are trying to grow a marijuana plant on your balcony-type area, and you are not sure of how much light it is actually getting. Know that light is one of THE deciding factors to your plant's survival and bud growth. No light, no bud, no plant. Second, you gotta make sure you're getting the right nutrients into the soil. The reason so many leaves are falling off, and the reason why bud growth is minimal, is because the plant is basically in a state of MALNUTRITION. It needs more food and light. Without them, it is going to die. If you cannot provide either, I regret to inform you that you are better off harvesting now, and ending it's suffering = ( Next time, try to start an indoor grow with a good light, with a few nutes on-hand.
Oh yeah, and black spots you are describing are probably spidermite eggs, eggs of some pests that are aiding in your plant's death. Those little buggers are munching on it, which is another reason why the leaves are falling off so quickly. This most likely occurs in outdoor grows, or indoor grow rooms that have not been sanitized/sealed off. You COULD go out and buy some bug-killer, but I completely forgot what kind it was best to use on marijuana at the moment, sorry...