No haven't had any red stems. I like FloraNova and would stay away from the miracle grow. It's just NPK, no micro or macro nutrients in that stuff. Once your plant uses up the nutes in the soil, use a fertilizer that has all the major and secondary nutrients like FloraNova or DynaGrow. Or keep it organic, I've heard good things about Earth Juice, it's organic and completely broken down already so goes directly to the roots and doesn't have to be broken down by the soil first, good even for hydro.
Or you could always repot once again with better soil and mix in shit like guanos and bone meal and shit. But thats when things get tricky. Keep it simple. I'll start a journal of the Sour Lemon Og once it gets to 6 or 7 weeks into flowering. And dude, if you get into soil and mixes, READ. The library has good stuff on organic soil growing. A lot of people forget about the library, thanks to the internets.