Hi, I'm in my second or third week of flowering and all three of my plants are turning yellow. I had a friend come over yesterday who has some experience, and we flushed them and i hope that fixes the problem. I don't wan't to wait three days to see if they get better, knowing they could die in those three days. My friend thinks i underwatered them but i don't think that is the case. I use a 600 watt hps right now with miracle grow soil and perlite. I might not have enough perlite in my mixture but they grew fine in veg within the big pots i had them in before i put them in flower. I have never used any fertilizers. I have pictures here and i appreciate anyones help who can help me diagnose the problem.