help with this plant please

I recently got a plant from a freind , i say its about 2 months old but im not sure.He was just growing this plant in his kitchen window and its winter and cold in new york.
He just used sunlight,and tap water. No nutes , he got the dirt from outside , no lights , no nothing , just a plant growing in 50-60 degrees and winter sunlight lol.And it didnt look too bad except the bottom half of the plant the fan leaves were yellowing and drooping.So i took the plant away from him and brouhgt it home.plant is a almost 3ft tall and was in a cut in half 2 liter with 3 small drain holes , so i repot in a 2 gallon pot.In doing so, i notice that the soil its in is fuckfested with all types of bugs i usualy see outside.So i decided only thing i can do to rid the bugs was to gently break up the root ball and wash off every last bit of dirt from the root. I did damage some smaller root while doing this but it got done . I had a bag of NewEra premix with time release nutes.I know time release can be bad but i figured this plant was toast and it was prety big already and may not get burned.For a few weeks it did nothing but droop.But it came back now and is growing nicely , its under 6x 42w cfls. Now.. the fan leaves that were dying pretty much stayed that way and new growth on the top and sides is coming but the leaves are coming out colored like the inside of the leaf is a nice green and then the outer tips and serations are a way lighter green and i have some leaf tips turnings cripsy.I dont have pics till my new phone comes but what does this sound like , my stems are also purple.Its definatly not heat. any input is a huge help ty

 

ya i think ur right tho, what can i do resolve the nute burn tho. trying to let some1 let me use their phone cam for pics asap