What's wrong with this Northen Lite?

Ok seriously,,what's wrong with this plant?
In the fall, a friend gave me a couple of northern lite babies which I veged for awhile and put them in the flowering tent along with a White widow that I managed to grow at 6 feet high and produced me a little more than a pound of marvelous buds,,But I had to cut down one of the northern lite because of root rot,,tghat one was pushing 5 feet tall when I cut it down unfortunatly but the other Northern only stayed at 2 feet high and refused to grow anymore,,the buds wqere small and managed to pull about an ounce and a half from it,,buds tasted really nice and gives you a powerful high,,but the Lites have given me problems since I got them,, WHY DO THEY LOOK SO FRAIL AND STRINGY?? I changed the soils twice, I don't overdo it with the nutes,,Humidity ranges between 50% and 60% ,,the PH is at the level it needs to be and I had some friends that have been growing for a long time scratch their heads wondering what's affecting them,,The only answer I have is it's probably because it's an OUTDOOR PLANT that don';t do so well in an enclosed climate in the house,,it's the only thing we can think about it at this time,,what do you guys think is wrong here,,have any of you encountered the same or siminliar issues bringing in an outdoor plant and growing it inside,,,please let me know,,I want to keep the strain alive so I can plant them outdoors this spring,,thanks ,,,,,,,,,,,,,,,,,,,,,,,,,As you can see the ones in the back of the tent are doing very well,,they are the white widows,,compare to the 2 northern lites in the front of picture,,,,,,

They grow fine indoors so that's not it.

I hope you don't mind if I brightened up the pics a bit:Attachment 283461Attachment 283462

It looks like a heat and water problem to me