It's not to late to clone but I can see you really want flower this big girl out. Gg#4 can triple it's height in flower. I have a gg#4 hybrid and it was like 2.5. in my experience low light levels exaggerate stretch in stretchy cultivars. She will be way to much plant for even 2 300 watt Mars. As for nutrients I would recommend Veg+Bloom from Hydroponics Research, it's an all in one powder. Great stuff...