Yellow Top leaves.. Help Please!!

Hi Everyone

Got a bit of a problem with one of my plants, A few days ago I started noticing the new leaves going yellow, I assumed it was a nute problem So I stopped with the nutes and have been watering them with bottled water since. but it doesnt seem to be making any difference, and has gotten worse since yesterday.

Here is what the plant looks like as of this morning.





It is a LSD, about 3 1/2 weeks old. Currently using a 600w cfl about 1.5ft away, along with a 250w blue cfl about 3 inches from the plants.

Any idea what the problem could be? Up until now this has been the healthiest of my plants...

Thanks in advance all

Hi..I'm new at this too and learning as I go along with my first grow as well. I read in a book by Billy McCann (Marijuana Home Grower's Manual) Under "Misconutrient Deficiencies (Fe,Mn,Zn,B,Cu,Mo) as follows...An iron deficiency is recognized by the yellowing of the leaf and the existence of the green vein; chlorosis starts at the base of the leaf and spreads.....
So I read where you were giving you plant some nutes and stopped , tried just giving them bottled water, but that isn't helping. I'm wondering did you check the PH level of the water, during the time you were feeding plants with the nutes, and also of the bottle water, because from what I read if the PH is too alkaline it will your plants to have nutrient lock up..... Any way I would PH my water before feeding and then check the PH level of the water from the run off after giving your plants a drink........good luck with your grow

How are your temps? If they are over 80 try to get em lower. Good advice by Dawnseal so do what he said if your temps are fine then if your ph is fine go get a cheap bottle of micro nutrients. Looks about like the iron def I got before but Like Dawnseal said could be ph causing it so check that before adding anything.