Rusty spots

Burning from chronic nitrogen toxicity, plain and simple. It is not a deficiency or a disease. You are feeding too much and/or too often. Autos get by just fine on half strength nutrients. In soil you need to adopt a schedule of plain water/plain water/feed/plain water/plain water/feed....... so that your plants are only being fed every 10-12 days, otherwise you get a build up of nutrient salts in the soil, which leads to the burning you are now experiencing. Try giving just plain water for the next ten days, before resuming with half strength feeds and your plant will recover and continue growing perfectly after that. At the moment your soil is over loaded with fertilizer. Flushing will not help, this can release even more nutrient salts and increase the burning exponentially. Just give plain water, in normal amounts and at normal intervals and in 10 days you should be right to go again, but at the moment she needs to consume whatever is in the soil first, before the introduction of any new nutrients. Hope this helps, Organoman.

Yeah Roberts is right. U have a potassium lock out because of bad PH (too high i think) I had the same with my Lemon Haze 2 years ago. Flush the soil untill u have the right PH value. 6,5 in soil is perfect. And then add some worm casting on the top layer.