4 out of 12 weeks flower, BD bag seed, supersoil, leaf disorder help?

hey guys, 3rd run with this particular bd bagseed. first time I fucked my light schedule, causing a reveg after 3 weeks of flower (total flower time was 14 weeks), second time was dont by friends of mine (they also fucked it up, took over 15 weeks). Its make or break time for this strain, and we're about 4 weeks in on this particular 8 headed mainlined plant, in a 7 gallon pot with super soil. the plant was top dressed a week before flower, and 2 weeks into flowering, but as you can see in the pics, some of the fan leaves are yellowing (only the largest of them), yet other leaves are clawing and acting like we might have overfed a little. what do you think my best course of action is to maintain plant health through this long flowering plant?

Setup ;
4x3.5x4h under a blickbustersix and generic 600 watt bulbs and mag ballasts. Temps = 70-74. Humidity 35-45. Supersoil, roots based, 7 gallon smartpot. The way this cycle worked out its the only plant in that chamber atm.

Meh. The smokes great, on oar with anything ive ever ordere sans the green phenobof aos. Overwatering may be the issue. Already have tried to fox the mg ossue but t seems to be getting worse. Was under the imression it wa dificult to have ph swings with ss ( water = 110 ppm, 6.7 ph out da tap).

Shes a bit sentamental at this point, pulled 5 oz under 260 watts of standard cfls in my bathroom/5 gallon pot with supersoil. Id def say if i can get the issue inder control i'll be looking at 5 more inder the 600.