Like I said for a plant that small it takes little moisture and probably no ferts to keep it going, although I can't understand why at 4+ weeks old it's only as tall as a cigarette?? Or are you talking the size of the main stalk? Just doesn't make any sense.

As for leaves that are brown and crispy? They do no good at all so take them off. Just make sure you cut close to the leaves and not right up next to the branch/stalk. Too close could promote disease in the branch/stalk as there's not much distance it has to cover to get there. The longer it is creates a sort of buffer.