Plant problem: Possibly Nitrogen defficiency?

Well, this is my plant that I stunted in growth. I'm just growing the one feminized fast bud right now, with 1 55 wat 2700, 1 42 wat 2700, and then the shop light over hang of 32 wat I think. Anway, I have a total of like 120 lumens atleast on the one plant so it should be good. I left it alone and it recovered good, but now its leaves are browning and dieing and I'm thinking that it may be due to nitrogen defficiency. I havne't given it any nutrients yet. Its an autoflower, and I'm growing it in a 50/50 mix of Fox Farm Ocean Forest soil and Light Warrior Natural seed starter which is perlite and vermiculite half and half basically among some other things. It recovered from the mishandeled transplant, and now its middle leaves are browning and dieing, and the tips and edges of the other leaves are doing the same. Its been about a month so about to start week 5. I'm growing it in a self watering pot that you fill up the bottom aquifer and it sucks it up from the bottom. Let me tell you, the root stem on this plant is amazing for cfl. Its a little bush. You cant move it. After I transplanted it I filled the bottom chamber with a gallon of rain water that I caught outside, and added one drop of superthrive to it. Super thrive = bush. Anyway, I didn't have to water it for about 2 weeks and it thrived. I filled it again and it was good for a week. I just watered it again yesterday and filled the bottom aquifer still with rain water. It should be good for another 5 days or so, but I was wondering if a pro could give me their diagnosis based on the picture.

Bump, any help would be appreciated please, I have to fix this this problem before I leave for xmas and it gets worse.

what leaves are being affected by the discoloration? older bigger ones, or all the newer small ones? the reddish browning tips im seein in your pics looks to me like a magnesium deficiency starting to take way. bout 5 weeks in? I would assume you should have been using a light nute mix a little sooner, a couple weeks after they were rooted and then just been slowly workin that ppm up. if you dig the Fox Farm products (thats what i use) go to their website and take a look at their watering schedule. research the nutes you intend to use and i think youll be surprised and how easily you find the solution. pickin up some FF Big Bloom and some FF Grow Big should be enough to get you started. (dont forget to grab your ph up and down!)

looks like heat burn rather then any other burn. how close is the light? and what kind? might try backing it off a bit.

Yeah the Ocean Forest is supposed to be good for the first month so it is time I start giving it nutes, but since its an auto flower I was just going to buy some foxfarm big bloom and only nute it for the flower stage but I guess that was a bad call. I'll go ahead and buy some nutes for it. Yeah its only the bigger older leaves being affected that are browning and dieing off.

And they're cfl's. About an inch or two away, they dont get too hot so I dont think its heat burn but I backed them up to about 3 inches now.