if you put about an inch of sand on top of the soil inside the pots, it will suffocate any larvae and eggs that are down there. i also put sand in my drainage plate under the pot to cover the drain holes. worked like a charm for me to get rid of the little fuckers
it grows better under a metal hallide, but the hps works as well. the hps produces more lumens per watt. so if you can only afford one HID light, it is suggested that you go with an hps.
do you have any pictures? with the hairs turning color, that doesnt sound like it would be dying but maturing. how are the leaves looking? how is the plant all together looking? droopy?