That looks like Chemdawg to me, it grows like that....could just be a screwy pheno. as far as your GO Box, with G O you really need to watch your PPM. if your not feeding around 1100-1300 your gonna get yellowing....but you also have to be very aware of build up in your medium with GO....i would get a PPM pen and PH pen from ebay and watch whats your levels are.....check your run off with your PPM pen to see what the parts per mill are.....you should be no more than 1500 more than 800