The best way to find out if root bound or not is to lift the plant up out of the pot and actually look.... This can be achieved by letting the soil dry a bit....simply tap the sides of the pot and it should come out fairly easy....just grab at the base of stalk and pull up.... If the plant's been in the pot for a month, chances are good that you'll have enough root growth to be able to perform this.... If that plant has been in there for less than a month, then I take back my root bound suggestion....

Is that a clay or plastic pot??? How many lamps you using??? How many watts you running??? Is the plant in a cabinet, room or just in the corner of a room??? What's your over all setup consist of???

CGI::::::