looks like root rot to me. kinda hard to fix that late into flowering. slow down on watering for a bit.
p.s. the damage is already done. you may have solved the problem. check for any new growth, this is your best sign.
deep water is best for power outages and will produce more per plant. NFT is for see of green. this web site has good info on hydro systems, Oh ya they sell cheap deep water systems too. http://clonebucket.com/hydro.htm
Looks like your using poor soil. when a plant is pail, with leaves curling upward, this tells me calcium deficiency. But calcium deficiency is often mistaken for improper ph. check ph levels and bring ph to 6.5-7. improper ph is often linked to poor soil conditions. Hydroponic growing is much...
your plant looks Ok to me. you might want to add a little nitrogen. when leaves turn yellow from the bottom up, it means your lacking nitrogen. worm casting spread over the top of your pot will solve the problem in a few days. here is a link to a web site who has professional fertilizer for...