TokenRing

I'm pretty sure my problem is nute burn, however I'v only used organic ferts. At the start of bloom I used PureBlend Pro with no problems, then I switched to biobizz Topmax(4 tablespoons per gallon) and I started running into problems.Plant is about 6 to 7 weeks into flower(sativa) I was using tap water with the ferts and watering once the pot was light.. I have all the classic signs of nute burn, Claw or curled shaped leaves, dead tips and margins, and yellow dots. Also the leaves are kinda dry and scraggely feeling, not soft.I already flushed the soil with a gallon and a half of bottled water. I have a Ph meter(soil probe) some spots measured 6.4 while other spots were 6.9 so if my meter is right I don't think I have any lockout except maybe Magnesium. A lot of leaves totally died, but the buds are fine. The leaf problem is all through out, not just the top or bottom of the plant. So i guess my question is can Topmax potentially burn the out of the plant or do I have some type of Nute defeciency?